I know the definition; I don't know the word.

It's a literary term for using an incorrect (but real) word in a sentence, BUT the correct word is obvious.
Example:

1) I'm surprised you noticed that; you're a very absorbent person.
(Absorbent is incorrectly used, but it's clear that the intended word was "observant")

2) We turned on our favorite soap opera, and forgot our troubles by gouging ourselves on ice cream (Gouging is incorrectly used, but it's clear that the intended word was "gorging")

There is a literary term for REAL words used incorrectly in a sentence, that are phonetically similar to the intended word.

(I'm sorry for the awkward description)