trifidadj.

trifid (adj.)"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).