The Collaborative International Dictionary of English v.0.48:
Believable \Be*liev"a*ble\, a. Capable of being believed; credible. -- Be*liev"a*ble*ness, n. -- Be*liev`a*bil"i*ty, n. [1913 Webster]WordNet (r) 3.0 (2006):
believable adj 1: capable of being believed; "completely credible testimony"; "credible information" [syn: credible, believable] [ant: incredible, unbelievable]