What is the definition of prefix in?

"In" is not a prefix. It's a preposition, a word that shows the relationship between a noun or pronoun and another word in the sentence.

Here's an example of "in" used as a preposition:

* The cat is in the box.

Here, "in" shows the location of the cat (inside the box).

Prefixes, on the other hand, are added to the beginning of a word to change its meaning. Some common prefixes are:

* un- (undo, unhappy)

* re- (redo, rewrite)

* pre- (pre-game, pre-paid)

* dis- (disagree, dislike)

If you are looking for a prefix related to "in", the closest one would be "in-" (like in "inactive" or "incorrect"). However, "in-" isn't always directly related to the preposition "in". It often indicates a state of "not" or "opposite of".