gratulation (n.)youdaoicibaDictYouDict[gratulation 词源字典]
late 15c., gratulacyon "expression of thanks," from Latin gratulationem (nominative gratulatio) "a manifestation of joy, wishing joy, rejoicing," from past participle stem of gratulari "give thanks, show joy," from gratus "agreeable" (see grace (n.)).[gratulation etymology, gratulation origin, 英语词源]