Webster’s Revised Unabridged Dictionary · 1913 Triungulus Tri·un′gu·lus (trī·ŭn′gū·lŭs), n.; pl. Triunguli (#). [NL. See Tri-, and Ungulate.] (Zoöl.) The active young larva of any oil beetle. It has feet armed with three claws, and is parasitic on bees. See Illust. of Oil beetle, under Oil. ‹ Triune Triunity ›