The term 'Punch Line' is used to refer to the humorous or ironic conclusion of a joke. The crossword solutions PAYOFF (6 letters), OUCH (4 letters), POW (3 letters), SCAR (4 letters), NUB (3 letters), and OOF (3 letters) all relate to this concept in some way. PAYOFF refers to the reward of laughter that comes from a successful punch line. OUCH and OOF are both exclamations of surprise or pain, which can be used to emphasize the punch line. POW and SCAR are both words that evoke physical violence, which can be used to create a humorous contrast with the punch line. Finally, NUB is a slang term for a joke that falls flat, which can be used to describe a punch line that fails to elicit laughter.