not proper; not strictly belonging, applicable, correct, etc.; erroneous: He drew improper conclusions from the scant evidence.
2.
not in accordance with propriety of behavior, manners, etc.: improper conduct at a funeral.
3.
unsuitable or inappropriate, as for the purpose or occasion: improper attire for a formal dance.
4.
abnormal or irregular: improper functioning of the speech mechanism.
Origin: 1535–45; < Latinimproprius. See im-2, proper
Related forms
im·prop·er·ly, adverb
im·prop·er·ness, noun
Synonyms 1–3. inapplicable, unsuited, unfit. 2. indecorous. Improper, indecent, unbecoming, unseemly are applied to that which is unfitting or not in accordance with propriety. Improper has a wide range, being applied to whatever is not suitable or fitting, and often specifically to what does not conform to the standards of conventional morality: improper diet; improper behavior in church; improper language.Indecent a strong word, is applied to what is offensively contrary to standards of propriety and especially of modesty: indecent behavior, literature.Unbecoming is applied to what is especially unfitting in the person concerned: conduct unbecoming a minister.Unseemly is applied to whatever is unfitting or improper under the circumstances: unseemly mirth.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.
an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
an extraordinary or unusual thing, person, or event; an exceptional example or instance.
1531 (implied in improperly) "not true," from Fr. impropre (14c.), from L. improprius, from in "not" + proprius (see proper). Meaning "not suited, unfit" is from 1570; that of "not in accordance with good manners, modesty, decency" is from 1739.