"Settle score" is a term that refers to dealing with a past conflict or grudge. However, there are many synonyms that can be used to convey this same meaning. Some such terms include "get back at," "revenge," "payback," "avenge," "retaliate," "settle a debt," and "square up." Each of these words has its own nuanced meaning, but all are ways to express the idea of addressing a perceived wrongdoing. Whether it involves taking action through physical or emotional means, the various synonyms for "settle score" convey a sense of satisfaction at righting a wrong.