1. influence or cause sth to happen
adversely/positively affect sales/change/productive
To 'affect' is usually related to pretence or influence As a verb it is used to talk about a change caused by another thing. "Pollution is affecting our climate". It can also mean to create an emotive response "The music affected the audience, moving them to tears". It can be used to say something was not genuine, "She affected a limp when challenged about her injury." This is often confused with 'effect' and in many cases, they are in fact interchangeable but not always. 'Affect' is more often used as a verb and 'effect' is more often used as a noun. This is a very common word that can be used in social or professional contexts.