Credible vs Credulous
Credibleadjective
capable of being believed
The difference
Credible means believable — a property of the claim. Credulous means too ready to believe — a property of the listener. A credible witness; a credulous audience.
How to keep them apart
Add creditable, meaning deserving praise, and you have three words one letter apart. Credible describes what is heard, credulous who hears it.