also: かげん
noun
Used when someone says something that goes beyond the truth, often in negative constructions like 過言ではない (it is no exaggeration to say).
彼が天才だと言っても過言ではない。
It is no exaggeration to say that he is a genius.
それは少し過言だと思う。
I think that's a bit of an overstatement.
noun
misstatement; gaffe; slip of the tongue
Refers to an unintentional mistake in speech, such as saying something incorrect or inappropriate. Less common than the exaggeration sense.
会議での彼の過言が問題になった。
His misstatement at the meeting became a problem.