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

1. to 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.

   Category: Pathology

4. (n.)feeling or emotion.

   Category: Psychiatry

5. Psychiatry. an expressed or observed emotional response.

   Category: Psychiatry

6. 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.)

1. to pretend or feign:

   to affect knowledge of history.

2. to assume artificially, pretentiously, or for effect:

   to affect a British accent.

3. to use, wear, or adopt by preference:

   to affect an outrageous costume.

4. to assume the character or attitude of:

   to affect the freethinker.

5. (of substances) to tend toward habitually or naturally:

   to affect colloidal form.

6. Archaic. to have affection for. to aspire to.

7. (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.)