Noun

1. The end or conclusion of something.

   Everyone come to our end-of-the-term wind-up party.

2. A punch line of a joke or comedy routine.
3. A joke, an attempt to fool someone or to make them angry.
   • 1999: Whatever Happened to Harold Smith? (movie)

     "Is this a wind-up, or what?" "No, no, it's true. He can really do it."

4. the part of a pitch where the pitcher moves his or her arm backwards before throwing the ball.
   • 1975: One Flew Over the Cuckoo's Nest (movie)

     He's into his wind-up. Here comes the pitch. Strike on the inside corner!

Adjective

1. needing to be wound up in order to function.
   • 1997, Daria (TV, episode 1.07):

     Maybe you could get a wind-up toy to distract him.