Zen (n.)youdaoicibaDictYouDict[Zen 词源字典]
school of Mahayana Buddhism, 1727, from Japanese, from Chinese ch'an, ultimately from Sanskrit dhyana "thought, meditation," from PIE root *dheie- "to see, look" (cognates: Greek sema "sign, mark, token"). As an adjective from 1881.[Zen etymology, Zen origin, 英语词源]