/ əˈfekt; NAmE / verb
1.
[ vn ] [ often passive ] to produce a change in sb/sth :
How will these changes affect us?
Your opinion will not affect my decision.
The south of the country was worst affected by the drought.
2.
[ vn ] [ often passive ] ( of a disease ) to attack sb or a part of the body; to make sb become ill / sick :
The condition affects one in five women.
Rub the cream into the affected areas.
3.
[ vn ] [ often passive ] to make sb have strong feelings of sadness, pity, etc. :
They were deeply affected by the news of her death.
4.
( formal ) to pretend to be feeling or thinking sth :
[ vn ]
She affected a calmness she did not feel.
[also v to inf ]
5.
[ vn ] ( formal , disapproving ) to use or wear sth that is intended to impress other people
SYN put on :
I wish he wouldn't affect that ridiculous accent.
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WHICH WORD
affect / effect
affect verb = 'to have an influence on sb/sth':
Does television affect children's behaviour?
It is not a noun.
effect noun = 'result, influence':
Does television have an effect on children's behaviour?
effect verb is quite rare and formal and means 'to achieve or produce'.
They hope to effect a reconciliation.
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WORD ORIGIN
senses 1 to 3 late Middle English (in the sense attack as a disease ): from French affecter or Latin affect- influenced, affected, from the verb afficere work on, influence, from ad- at, to + facere do.
senses 4 to 5 late Middle English : from French affecter or Latin affectare aim at, frequentative of afficere work on, influence, from ad- at, to + facere do. The original sense was like, love , hence (like to) use, assume, etc. .