What is the definition of the word incredulous, based on its parts?

"not without growth"

"causing belief"

"without causing growth"

"full of disbelief"

''full of disbelief''

The meaning of the word incredulous, based on its parts is: "full of disbelief".

The prefix in - is one of the many prefixes that mean "no". So it denies the meaning of the word following it. One example would be the word inefficient. By adding the prefix in - to the adjective efficient, we deny the adjective. If we call a person inefficient, we are saying the person is "not efficient", not able to finish tasks in a proper time and manner.

As for the other part of the word we're analyzing here, "credulous" comes from the Latin word "credere", which means "believe". A credulous person is a person who believes in things easily, without questioning or reasoning.

By putting in - and credulous together, we form "incredulous", or "not credulous". So an incredulous person is a person who does not believe easily - who is full of disbelief.