trifid (adj.)youdaoicibaDictYouDict[trifid 词源字典]
"divided into three lobes," 1620s, from Latin trifidus "cleft in three," from tri- "three" (see tri-) + -fid. This adjective probably inspired triffid, the name of the three-legged walking poisonous plants in John Wyndham's novel "The Day of the Triffids" (1951).[trifid etymology, trifid origin, 英语词源]
tripod (n.)youdaoicibaDictYouDict
c. 1600, "three-legged vessel," c. 1600, from Latin tripus (genitive tripodis), from Greek tripous (genitive tripodos) "a three-legged stool or table," noun use of adjective meaning "three-footed," from tri- "three" (see tri-) + pous (genitive podos) "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). Related: Tripodal.
triskelion (n.)youdaoicibaDictYouDict
"figure consisting of three branches radiating from a center," 1880, earlier triskelos (1857), from Greek triskeles "three-legged," from tri- "three" (see tri-) + skelos "leg" (see scoliosis).
trivet (n.)youdaoicibaDictYouDict
three-legged iron stand, 12c., trefet, probably from a noun use of Latin tripedem (nominative tripes) "three-footed," from tri- "three" (see three) + pes "foot," from PIE root *ped- (1) "a foot" (see foot (n.)).