'change-up' definitions:

Definition of 'change-up'

From: WordNet
noun
A baseball thrown with little velocity when the batter is expecting a fastball [syn: change-up, change-of-pace, change-of-pace ball, off-speed pitch]

Definition of 'change-up'

From: GCIDE
  • change-of-pace \change-of-pace\ n. (Baseball) a baseball pitch thrown with little velocity when the batter is expecting a fastball; -- called also change-up.
  • Syn: change-up, change-of-pace ball, off-speed pitch. [WordNet 1.5]

Definition of 'change-up'

From: GCIDE
  • change-up \change-up\ n. (Baseball) same as change-of-pace.
  • Syn: change-of-pace, change-of-pace ball, off-speed pitch. [WordNet 1.5]