The Collaborative International Dictionary of English v.0.48:
crapper \crap"per\ (kr[a^]p"p[~e]r), n. a toilet. [vulgar] Syn: toilet, can, commode, pot, potty, stool, throne. [WordNet 1.5 + PJC]WordNet (r) 3.0 (2006):
crapper n 1: a plumbing fixture for defecation and urination [syn: toilet, can, commode, crapper, pot, potty, stool, throne]