Requiring great effort or endurance: a hard assignment.
Performed with or marked by great diligence or energy: a project that required years of hard work.
Difficult to resolve, accomplish, or finish: That was a hard question.
Difficult to understand or impart: Physics was the hardest of my courses. Thermodynamics is a hard course to teach.
Intense in force or degree: a hard blow.
Inclement: a long, hard winter.
Stern or strict in nature or comportment: a hard taskmaster.
Resistant to persuasion or appeal; obdurate.
Making few concessions: drives a hard bargain.
Difficult to endure: a hard life.
Oppressive or unjust in nature or effect: restrictions that were hard on welfare applicants.
Lacking compassion or sympathy; callous.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Requiring great effort or endurance: a hard assignment.
Performed with or marked by great diligence or energy: a project that required years of hard work.
Difficult to resolve, accomplish, or finish: That was a hard question.
Difficult to understand or impart: Physics was the hardest of my courses. Thermodynamics is a hard course to teach.
Intense in force or degree: a hard blow.
Inclement: a long, hard winter.
Stern or strict in nature or comportment: a hard taskmaster.
Resistant to persuasion or appeal; obdurate.
Making few concessions: drives a hard bargain.
Difficult to endure: a hard life.
Oppressive or unjust in nature or effect: restrictions that were hard on welfare applicants.
Lacking compassion or sympathy; callous.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Intense in force or degree: a hard blow.
Inclement: a long, hard winter.
Stern or strict in nature or comportment: a hard taskmaster.
Resistant to persuasion or appeal; obdurate.
Making few concessions: drives a hard bargain.
Difficult to endure: a hard life.
Oppressive or unjust in nature or effect: restrictions that were hard on welfare applicants.
Lacking compassion or sympathy; callous.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Stern or strict in nature or comportment: a hard taskmaster.
Resistant to persuasion or appeal; obdurate.
Making few concessions: drives a hard bargain.
Difficult to endure: a hard life.
Oppressive or unjust in nature or effect: restrictions that were hard on welfare applicants.
Lacking compassion or sympathy; callous.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Difficult to endure: a hard life.
Oppressive or unjust in nature or effect: restrictions that were hard on welfare applicants.
Lacking compassion or sympathy; callous.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Harsh or severe in effect or intention: said some hard things that I won't forget.
Bitter; resentful: No hard feelings, I hope.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Causing damage or premature wear: Snow and ice are hard on a car's finish.
Bad; adverse: hard luck.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Proceeding or performing with force, vigor, or persistence; assiduous: a hard worker.
Real and unassailable: hard evidence.
Definite; firm: a hard commitment.
Close; penetrating: We need to take a hard look at the situation.
Free from illusion or bias; practical: brought some hard common sense to the discussion.
Using or based on data that are readily quantified or verified: the hard sciences.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Marked by sharp outline or definition; stark.
Lacking in delicacy, shading, or nuance.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Hard-core.
Being a turn in a specific direction at an angle more acute than other possible routes.
Metallic, as opposed to paper. Used of currency.
Backed by bullion rather than by credit. Used of currency.
High and stable. Used of prices.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Durable; lasting: hard merchandise.
Written or printed rather than stored in electronic media: sent the information by hard mail.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Erect; tumid. Used of a penis.
Having high alcoholic content; intoxicating: hard liquor.
Rendered alcoholic by fermentation; fermented: hard cider.
Containing dissolved salts that interfere with the lathering action of soap. Used of water.
Linguistics Velar, as in c in cake or g in log, as opposed to palatal or soft.
Physics Of relatively high energy; penetrating: hard x-rays.
High in gluten content: hard wheat.
Chemistry Resistant to biodegradation: a hard detergent.
Physically addictive. Used of certain illegal drugs, such as heroin.
Resistant to blast, heat, or radiation. Used especially of nuclear weapons.
adv.
With strenuous effort; intently: worked hard all day; stared hard at the accused criminal.
With great force, vigor, or energy: pressed hard on the lever.
In such a way as to cause great damage or hardship: industrial cities hit hard by unemployment.
With great distress, grief, or bitterness: took the divorce hard.
Firmly; securely: held hard to the railing.
Toward or into a solid condition: concrete that sets hard within a day.
Near in space or time; close: The factory stands hard by the railroad tracks.
Nautical Completely; fully: hard alee.
[Middle English, from Old English heard; see kar- in Indo-European roots.]
Synonyms: These adjectives mean requiring great physical or mental effort to do, achieve, or master. Hard is the most general term: "You write with ease to show your breeding,/But easy writing's curst hard reading" (Richard Brinsley Sheridan). Difficult and hard are interchangeable in many instances. Difficult, however, is often preferable where the need for skill or ingenuity is implied: "All poetry is difficult to read,/—The sense of it is, anyhow" (Robert Browning). Arduous applies to burdensome labor or sustained physical or spiritual effort: "knowledge at which [Isaac] Newton arrived through arduous and circuitous paths" (Thomas Macaulay).
Defined, fixed, invariable, as in We have hard and fast rules for this procedure. This term originally was applied to a vessel that has come out of water, either by running aground or being put in dry dock, and is therefore unable to move. By the mid-1800s it was being used figuratively.
[hahrd-n-fast, -fahst] 
