credibilˈity /kred-/ noun

1. The quality of deserving belief or confidence
2. The amount of confidence placed in one on the basis of one's record, knowledge or proven abilities, eg in a particular social group or environment

credˈibleness noun

credˈibly adverb

credibility gap noun (politics, etc)

The discrepancy between what is claimed or stated and what actually is, or seems likely to be, the case