The Collaborative International Dictionary of English v.0.48:
Accuser \Ac*cus"er\, n. [OE. acuser, accusour; cf. OF. acuseor, fr. L. accusator, fr. accusare.] One who accuses; one who brings a charge of crime or fault. [1913 Webster]WordNet (r) 3.0 (2006):
accuser n 1: someone who imputes guilt or blame