to act on; produce an effect or change in: Cold weather affected the crops.
2.
to impress the mind or move the feelings of: The music affected him deeply.
3.
(of pain, disease, etc.) to attack or lay hold of.
–noun
4.
Psychology. feeling or emotion.
5.
Psychiatry. an expressed or observed emotional response: Restricted, flat, or blunted affect may be a symptom of mental illness, especially schizophrenia.
6.
Obsolete. affection; passion; sensation; inclination; inward disposition or feeling.
[Origin: 1350–1400; ME < L affectus acted upon, subjected to; mental or emotional state (ptp. and action n. of afficere), equiv. to af-af-+ fec- (comb. form of facere to make, do) + -tus action n. suffix or -tus ptp. suffix]
—Usage note Affect1 and effect, each both noun and verb, share the sense of “influence,” and because of their similarity in pronunciation are sometimes confused in writing. As a verb affect1 means “to act on” or “to move” (His words affected the crowd so deeply that many wept); affect2 means “to pretend” or “to assume” (new students affecting a nonchalance they didn't feel). The verb effect means “to bring about, accomplish”: Her administration effected radical changes. The noun effect means “result, consequence”: the serious effects of the oil spill. The noun affect1 pronounced with the stress on the first syllable, is a technical term in psychology and psychiatry. Affect2 is not used as a noun.
to give the appearance of; pretend or feign: to affect knowledge of the situation.
2.
to assume artificially, pretentiously, or for effect: to affect a Southern accent.
3.
to use, wear, or adopt by preference; choose; prefer: the peculiar costume he affected.
4.
to assume the character or attitude of: to affect the freethinker.
5.
(of things) to tend toward habitually or naturally: a substance that affects colloidal form.
6.
(of animals and plants) to occupy or inhabit; live in or on: Lions affect Africa. Moss affects the northern slopes.
7.
Archaic.
a.
to have affection for; fancy.
b.
to aim at; aspire to.
–verb (used without object)
8.
Obsolete. to incline, tend, or favor (usually fol. by to): He affects to the old ways.
[Origin: 1400–50; late ME < MF affecter < L affectāre to strive after, feign (freq. of afficere to do to), equiv. to af-af-+ fec- (see affect1) + -tāre freq. suffix]
To have an influence on or effect a change in: Inflation affects the buying power of the dollar.
To act on the emotions of; touch or move.
To attack or infect, as a disease: Rheumatic fever can affect the heart.
n.
(āf'ěkt')
Feeling or emotion, especially as manifested by facial expression or body language: "The soldiers seen on television had been carefully chosen for blandness of affect"(Norman Mailer).
Obsolete A disposition, feeling, or tendency.
[Middle English affecten, from Latin afficere, affect-, to do to, act on : ad-, ad- + facere, to do; see dhē- in Indo-European roots.]
Synonyms: These verbs mean to produce a mental or emotional effect. To affect is to act upon a person's emotions: Adverse criticism of the book didn't affect the author. Influence implies some control over the thinking, actions, and emotions of another: "Humanity is profoundly influenced by what you do" (Pope John Paul II).
To impress is to produce a marked, often enduring effect: "The Tibetan landscape particularly impressed him" (Doris Kerns Quinn).
Touch usually means to arouse a tender response: "The tributes [to the two deceased musicians] were fitting and touching" (Daniel Cariaga).
Move suggests a profound emotional effect: The account of her experiences moved us to tears. Strike implies keenness or force of mental response: I was struck by the sudden change in his appearance.
Usage Note: Affect and effect have no senses in common. As a verb affect is most commonly used in the sense of "to influence" (how smoking affects health). Effect means "to bring about or execute": layoffs designed to effect savings. Thus the sentence These measures may affect savings could imply that the measures may reduce savings that have already been realized, whereas These measures may effect savings implies that the measures will cause new savings to come about.
c.1374, "mental state," from L. affectus, pp. of afficere "act on, have influence on," a verb of broad meaning, from ad- "to" + facere (pp. factus) "do" (see factitious). The verb meaning "to make an impression on" is attested from 1631.
"to make a pretense of," 1661, earlier "to assume the character of (someone)" (1591); originally in Eng. "to aim at, aspire to, make for" (1483), from M.Fr. affecter (15c.), from L. affectare "to strive after, aim at," freq. of afficere (pp. affectus) "to do something to, act on" (see affect (n.)).
Af*fect"\ ([a^]f*f[e^]kt"), v. t. [imp. & p. p. Affected; p. pr. & vb. n. Affecting.] [L. affectus, p. p. of afficere to affect by active agency; ad + facere to make: cf. F. affectere, L. affectare, freq. of afficere. See Fact.]1. To act upon; to produce an effect or change upon. As might affect the earth with cold heat. --Milton. The climate affected their health and spirits. --Macaulay. 2. To influence or move, as the feelings or passions; to touch. A consideration of the rationale of our passions seems to me very necessary for all who would affect them upon solid and pure principles. --Burke. 3. To love; to regard with affection. [Obs.] As for Queen Katharine, he rather respected than affected, rather honored than loved, her. --Fuller. 4. To show a fondness for; to like to use or practice; to choose; hence, to frequent habitually. For he does neither affect company, nor is he fit for it, indeed. --Shak. Do not affect the society of your inferiors in rank, nor court that of the great. --Hazlitt. 5. To dispose or incline. Men whom they thought best affected to religion and their country's liberty. --Milton. 6. To aim at; to aspire; to covet. [Obs.] This proud man affects imperial ?way. --Dryden. 7. To tend to by affinity or disposition. The drops of every fluid affect a round figure. --Newton. 8. To make a show of; to put on a pretense of; to feign; to assume; as, to affect ignorance. Careless she is with artful care, Affecting to seem unaffected. --Congreve. Thou dost affect my manners. --Shak. 9. To assign; to appoint. [R.] One of the domestics was affected to his special service. --Thackeray. Syn: To influence; operate; act on; concern; move; melt; soften; subdue; overcome; pretend; assume.
![[P]](http://cache.lexico.com/g/d/premium_mh.gif){kind=small}
Audio Help [v. uh-fekt; n. af-ekt] Pronunciation Key 
