1540s, from supreme + -acy, or from Latin supremitatem (nominative supremitas). Supremity in same sense is from 1530s.

domination: power to dominate or defeat; "mastery of the seas" Supremacy is the fourth album from the metalcore band Hatebreed and their first with record label Roadrunner Re [..]

a set of beliefs whereby one group is deemed superior to another and thus justified in assuming a dominant hierarchical relationship. Prejudice facilitates supremacy, but they are distinct, though linked, phenomena. Racism, sexism, heterosexism, and antisemitism are the major forms of supremacy in the U.S., but there are others based on ability, la [..]

(n) power to dominate or defeat

Historically, the supremacy of the English king over the English Church, i.e. the king not the Pope is acknowledged as the supreme head of the Church of England. Established legally by the Act of Supr [..]