Mid 19th century; earliest use found in Philip Gosse (1810–1888), zoologist and religious writer. From pro- + ancient Greek χρόνος time + -ic, after chronic.
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。