purgatory (n.)youdaoicibaDictYouDict[purgatory 词源字典]
c. 1200, from Old French purgatore and directly from Medieval Latin purgatorium (St. Bernard, early 12c.), in Latin, "means of cleansing," noun use of neuter of purgatorius (adj.) "purging, cleansing," from purgat-, past participle stem of Latin purgare (see purge (v.)). Figurative use from late 14c.[purgatory etymology, purgatory origin, 英语词源]