make a counterattack and return like for like, especially evil for evil; "The Empire strikes back"; "The Giants struck back and won the opener"; "The Israeli army retaliated for the Hamas bombing"
an adequate quantity; a quantity that is large enough to achieve a purpose; "enough is as good as a feast"; "there is more than a sufficiency of lawyers in this country"
as much as necessary; "Have I eaten enough?"; (`plenty' is nonstandard) "I've had plenty, thanks"