affect1

[v. uh-fekt; n. af-ekt] /v. əˈfɛkt; n. ˈæf ɛkt/
verb (used with object)
1.
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; Middle English < Latin affectus acted upon, subjected to; mental or emotional state (past participle and action noun of afficere), equivalent to af- af- + fec- (combining form of facere to make, do) + -tus action noun suffix or -tus past participle suffix
Related forms
affectable, adjective
affectability, noun
Synonyms
1. influence, sway; modify, alter. 2. touch, stir.
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.

affect2

[uh-fekt] /əˈfɛkt/
verb (used with object)
1.
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.
  1. to have affection for; fancy.
  2. to aim at; aspire to.
verb (used without object)
8.
Obsolete. to incline, tend, or favor (usually followed by to):
He affects to the old ways.
Origin
1400-50; late Middle English < Middle French affecter < Latin affectāre to strive after, feign (frequentative of afficere to do to), equivalent to af- af- + fec- (see affect1) + -tāre frequentative suffix
Related forms
affecter, noun
Synonyms
1. See pretend.
Usage note
See affect1.
Examples from the web for affect
  • The chemical often referred to as the bonding hormone has already been shown to affect the social skills of people with autism.
  • Over time, these cycles affect personality development.
  • In theory, virtual currency could affect money supply.
  • No one knows at what point tax burdens truly affect investment and productivity.
  • Smoking is a familiar example of how our behaviors can affect our genes.
  • In my experience, teachers' opinions don't affect students.
  • But the ripples from the subprime crisis are now beginning to affect nearly everyone.
  • His guilt was enormous-the other side of his belief in his powers to affect the world around him.
  • We're finally beginning to understand how concussion affect players post-career--depression for example.
  • Briefly discusses whether or not gifts affect the way teachers grade.
British Dictionary definitions for affect

affect1

verb (transitive) (əˈfɛkt)
1.
to act upon or influence, esp in an adverse way: damp affected the sparking plugs
2.
to move or disturb emotionally or mentally: her death affected him greatly
3.
(of pain, disease, etc) to attack
noun (ˈæfɛkt; əˈfɛkt)
4.
(psychol) the emotion associated with an idea or set of ideas See also affection
Word Origin
C17: from Latin affectus, past participle of afficere to act upon, from ad- to + facere to do

affect2

/əˈfɛkt/
verb (mainly transitive)
1.
to put on an appearance or show of; make a pretence of: to affect ignorance
2.
to imitate or assume, esp pretentiously: to affect an accent
3.
to have or use by preference: she always affects funereal clothing
4.
to adopt the character, manner, etc, of: he was always affecting the politician
5.
(of plants or animals) to live or grow in: penguins affect an arctic climate
6.
to incline naturally or habitually towards: falling drops of liquid affect roundness
Word Origin
C15: from Latin affectāre to strive after, pretend to have; related to afficere to affect1
Word Origin and History for affect
n.

late 14c., "mental state," from Latin noun use of affectus "furnished, supplied, endowed," figuratively "disposed, constituted, inclined," past participle of afficere "to do; treat, use, manage, handle; act on; have influence on, do something to," a verb of broad meaning, from ad- "to" (see ad-) + facere (past participle factus) "do" (see factitious). Perhaps obsolete except in psychology. Related: Affects.

v.

"to make an impression on," 1630s; earlier "to attack" (c.1600), "act upon, infect" (early 15c.), from affect (n.). Related: Affected; affecting.

"to make a pretense of," 1660s, earlier "to assume the character of (someone)" (1590s); originally in English "to aim at, aspire to, desire" (early 15c.), from Middle French affecter (15c.), from Latin affectare "to strive after, aim at," frequentative of afficere (past participle affectus) "to do something to, act on" (see affect (n.)). Related: Affected; affecting.

affect in Medicine

affect af·fect (ə-fěkt')
v. af·fect·ed, af·fect·ing, af·fects

  1. To have an influence on or affect a change in.

  2. To attack or infect, as a disease.

n. (āf'ěkt')

  1. A feeling or emotion as distinguished from thought, or action.

  2. A strong feeling with active consequences.