Quick answer
Credible describes something believable — a credible account. Credulous describes a person who believes too readily — gullible. The thing is credible; the person is credulous. And credulous is not a compliment.
The core difference
A quality of the claim and a quality of the listener.
- credible — believable: a credible threat, a credible witness.
- credulous — too ready to believe: a credulous audience.
The pattern
Identical in shape to incredible vs incredulous: -ible describes the thing, -ulous describes the person. Learning one pair gives you both.
The related words
Credulity is the readiness to believe — strains credulity means it is too much to swallow. Credence is belief given to something — lend credence to. Both come from Latin credere, to believe, along with credit and creed.
Frequently asked questions
Which word describes a person?
Credulous — too ready to believe. Credible describes the claim.
What does "strains credulity" mean?
It is too far-fetched to believe — credulity being the willingness to believe.
Is there a matching pair?
Yes — incredible and incredulous follow exactly the same -ible/-ulous pattern.
