'Believability' definitions:

Definition of 'believability'

From: WordNet
noun
The quality of being believable or trustworthy [syn: credibility, credibleness, believability] [ant: incredibility, incredibleness]

Definition of 'Believability'

From: GCIDE
  • 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]