1. Derived words are credibility, credibly, and Credibleness

2. Attribute: believability; credibility; credibleness (the quality of being Believable or trustworthy)

3. Cogency: 1 n the quality of being valid and rigorous Synonyms: rigor , rigour , validity Type of: believability , credibility , credibleness the quality of being believable or trustworthy n persuasive relevance Type of: relevance , relevancy the relation of something to the matter at hand