noun
changeup
A slow pitch in baseball that looks like a fastball but arrives much slower, disrupting the batter's timing.
彼のチェンジアップは打者のタイミングを外すのに効果的だ。
His changeup is effective at disrupting the batter's timing.
A fastball; チェンジアップ is a slow pitch that mimics a fastball's arm motion.
A curveball; チェンジアップ relies on speed change rather than breaking movement.
Borrowed from English 'changeup', a baseball term for a slow pitch.