Early 17th century; earliest use found in George Carleton (?1558–1628), bishop of Chichester. From un- + retract + -able.
Late 19th century; earliest use found in Samuel David Gross (1805–1884). From un- + retractable.
英语词典包含243303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。