What is the root word of incredible?

The root word of "incredible" is cred, which comes from the Latin word credere meaning "to believe."

Here's the breakdown:

* In-: A prefix meaning "not" or "the opposite of"

* Cred: The root word meaning "to believe"

* -ible: A suffix meaning "capable of" or "able to be"

Therefore, "incredible" literally means "not able to be believed" or "unbelievable."