Lĭt'ŭ-ŭs, n.

n. [Lat.] 1. (Rom. Antiq.) (a.) A curved staff used by the augurs in quartering the heavens. (b.) An instrument of martial music; a kind of trumpet of a somewhat curved form and shrill note. 2. (Math.) A kind of spiral, the same as would be described by the circumferential extremity of one side of a circular sector of constant area but variable radius, the other side of which is fixed.