you know what?
idiomDefinition of you know what?
(Entry 1 of 2)
informal
1
—used to emphasize the statement that comes after it You know what? I never trusted her.She lied to me again, but you know what? I really just don't care anymore.
2
—used to get someone's attention Hey, you know what? I'm hungry.
you-know-what
nounDefinition of you-know-what (Entry 2 of 2)
informal
1
—used in speech to refer to something that is not named but is known to both the hearer and speaker I've hidden the you-know-what in the closet.
2
—used in place of a rude or offensive word in order to express anger or annoyance He's a complete you-know-what.