tantra (n.)youdaoicibaDictYouDict[tantra 词源字典]
type of Hindu religious book, 1799, from Sanskrit tantram, literally "loom, warp," hence, figuratively, "groundwork, system, doctrine," from tan "to stretch, extend," from PIE root *ten- "to stretch, extend" (see tenet).[tantra etymology, tantra origin, 英语词源]