Definitions for affectəˈfɛkt; ˈæf ɛkt

Random House Webster's College Dictionary

af•fect^*əˈfɛkt; ˈæf ɛkt(v.; n.; v.t.)

to produce an effect or change in:
Cold weather affected the crops.
to impress the mind or move the feelings of:
The music affected him deeply.
(of pain, disease, etc.) to attack or lay hold of.
Category: Pathology
(n.)feeling or emotion.
Category: Psychiatry
Psychiatry. an expressed or observed emotional response.
Category: Psychiatry
Obs. inward disposition or feeling.

^* Usage: Because of similarity in pronunciation, affect and effect are sometimes confused in writing. The spelling affect is used of two different words. The verb affect1 means “to act on” or “to move” (His words affected the crowd so deeply that many wept); the noun affect1, pronounced with the stress on the first syllable, refers to emotion or, in psychiatry, emotional response. affect2 is not used as a noun; as a verb it 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.

Origin of affect:

1350–1400; ME, < L affectus

af•fect`a•bil′i•ty(n.)

af•fect^*əˈfɛkt(v.t.)

to pretend or feign:
to affect knowledge of history.
to assume artificially, pretentiously, or for effect:
to affect a British accent.
to use, wear, or adopt by preference:
to affect an outrageous costume.
to assume the character or attitude of:
to affect the freethinker.
(of substances) to tend toward habitually or naturally:
to affect colloidal form.
Archaic. to have affection for. to aspire to.
(v.i.)Obs. to incline:
She affects to the old ways.

^* Syn: See pretend.Usage: See affect1.

Origin of affect:

1400–50; late ME < MF affecter < L affectāre

af•fect′•er(n.)

Princeton's WordNet

affect(verb)
the conscious subjective aspect of feeling or emotion
affect, impact, bear upon, bear on, touch on, touch(verb)
have an effect upon
"Will the new rules affect me?"
affect(verb)
act physically on; have an effect upon
"the medicine affects my heart rate"
involve, affect, regard(verb)
connect closely and often incriminatingly
"This new ruling affects your business"
feign, sham, pretend, affect, dissemble(verb)
make believe with the intent to deceive
"He feigned that he was ill"; "He shammed a headache"
affect, impress, move, strike(verb)
have an emotional or cognitive impact upon
"This child impressed me as unusually mature"; "This behavior struck me as odd"

Kernerman English Learner's Dictionary

affect(verb)əˈfɛkt
to change or influence
The disease affects the animal's brain.; car sales affected by high gas prices

Webster Dictionary

Affect(verb)
to act upon; to produce an effect or change upon
Affect(verb)
to influence or move, as the feelings or passions; to touch
Affect(verb)
to love; to regard with affection
Affect(verb)
to show a fondness for; to like to use or practice; to choose; hence, to frequent habitually
Affect(verb)
to dispose or incline
Affect(verb)
to aim at; to aspire; to covet
Affect(verb)
to tend to by affinity or disposition
Affect(verb)
to make a show of; to put on a pretense of; to feign; to assume; as, to affect ignorance
Affect(verb)
to assign; to appoint
Affect(noun)
affection; inclination; passion; feeling; disposition

U.S. National Library of Medicine

Affect
The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves.