(In a steam engine) a spring-loaded safety valve designed to open or close very rapidly at a predetermined pressure.
Late 19th century; earliest use found in Buyers' Guide & Mechanics' Manual.
英语词典包含464360条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。