Definitions for "punch line"
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.
The final sentence, phrase, or word in any narration, speech, or advertisement that produces the speaker's intended effect.
the second part of a joke that contains a reinterpretation that creates a 2nd story that shatters the setup's decoy assumption.
Keywords:  blueprint, outline, draw, view, plan
The outline of the draw punch in the plan view of a blueprint
(same as punch).