[get back at] {v.}, {informal} To do something bad to (someone who has done something bad to you) hurt in return.
* /John played a joke on Henry, and next day Henry got back at him./* /The elephant waited many years to get back at the man who fed him red pepper./
Syn.: PAY BACK, SETTLE A SCORE, TIT FOR TAT. Compare: GET AT(2), GET EVEN.