What is malapropism? Is there a movie that has some sort of malapropism in it?

Malapropism is the mistaken use of a word in place of a similar-sounding word.

The misuse of a word in a malapropism is typically amusing in nature. Here are a couple of examples of malapropisms in movies:

Back to the II

Young Biff: Why don't you make like a tree, and get out of here?Old Biff: (Dope Slap) It's leave*, you idiot! "Make like a tree, and leave."!

Fired Up

Coach Keith (talking to a group of cheerleaders): That's prohibidado (he means: prohibido). I told them in Spanish, how much clearer could I have been!

Both are fantastic movies.

I hope this helps!