tete-a-tete (n.)youdaoicibaDictYouDict[tete-a-tete 词源字典]
"a private meeting," from French tête-à-tête, literally "head-to-head," from Old French teste "head" (see tete). The adjective, "private, confidential, with none present but the persons concerned" is recorded from 1728; as an adverb from 1790.[tete-a-tete etymology, tete-a-tete origin, 英语词源]