punch line

n.	1.	The final sentence, phrase, or word in a joke or humorous story that is unexpected and produces the humorous effect; the point of a joke.
	2.	The final sentence, phrase, or word in any narration, speech, or advertisement that produces the speaker's intended effect.

Noun

1.

punch line - the point of a joke or humorous story Synonyms: gag line, tag line, laugh line

gag, gag line, jape, jest, joke, laugh, laugh line, line, tag line