Jockey
noun
手 takes its alternative meaning "doer" here, so that gives us horse riding doer. Who does horse riding? It’s a jockey.
This word usually refers to a professional or skilled rider in horse racing or equestrian sports.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その騎手は、自分の初めてのG1レースの日に朝寝坊をしました。
The jockey overslept on the day of his first G1 race.