Wiktionary
accusator
n. (context archaic English) A male accuser;The '''Oxford English Dictionary''' (2007)
Usage examples of "accusator".
Glanvill says it belongs to the sheriff, in case of neglect on the part of lords of franchise, to take cognizance of melees, blows, and even wounds, unless the accuser add a charge of breach of the king's peace (nisi accusator adjiciat de pace Domini Regis infracta).