Technical term in horology; the mechanism in a clock or watch that controls the release of energy from the mainspring.
機械式時計の脱進機は、正確な時間を刻むために重要な部品です。
The escapement of a mechanical watch is an important component for keeping accurate time.
Compound of 脱 (escape) + 進 (advance) + 機 (mechanism), likely a calque from Western horological terminology.