What is verb of credibility?

There isn't a single verb that perfectly captures the idea of "credibility." However, depending on the specific context, you could use several verbs that convey similar meanings:

Verbs implying a sense of trustworthiness:

* Believe: "I believe her story."

* Trust: "We trust him with our secrets."

* Confide: "She confided in her best friend."

* Rely: "We can rely on their expertise."

* Validate: "The research validates her claims."

Verbs implying a sense of truthfulness or authenticity:

* Verify: "We need to verify the information."

* Confirm: "The witness confirmed the suspect's alibi."

* Authenticate: "The document was authenticated by an expert."

* Substantiate: "The evidence substantiates the allegations."

* Prove: "The lawyer tried to prove his client's innocence."

Verbs implying a sense of being recognized as an authority:

* Establish: "He has established himself as an expert in the field."

* Gain: "She gained credibility through years of experience."

* Earn: "The company has earned a reputation for reliability."

* Command: "His arguments command respect."

* Inspire: "Her leadership inspires confidence."

The best verb to use will depend on the specific situation and the nuance you want to convey.