ostentatious (adj.)youdaoicibaDictYouDict[ostentatious 词源字典]
1701, from ostentation + -ous. Earlier in a similar sense were ostentative (c. 1600); ostentive (1590s). Related: Ostentatiously; ostentatiousness (1650s).[ostentatious etymology, ostentatious origin, 英语词源]