Source : Webster's Revised Unabridged Dictionary (1913)

Triungulus \Tri*un"gu*lus\, n.; pl. {Triunguli}. [NL. See
   {Tri-}, and {Ungulate}.] (Zo["o]l.)
   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}.