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"
the size of something as given by the distance around it
the length of the closed curve of a circle
the boundary line encompassing an area or object; "he had walked the full circumference of his land"; "a danger to all races over the whole circumference of the globe"