Webster's Revised Unabridged Dictionary · 1913

Troilus

Troilus , noun

[New Latin, from Latin Troilus, Greek {not transcribed}, the son of Priam.]

(Zoology) A large, handsome American butterfly (Euphoades troilus, or Papilio troilus). It is black, with yellow marginal spots on the front wings, and blue spots on the rear wings; -- also called troilus butterfly.