1. (n.) A curved staff used by the augurs in quartering the heavens.

2. (n.) An instrument of martial music; a kind of trumpet of a somewhat curved form and shrill note.

3. (n.) A spiral whose polar equation is r2/ = a; that is, a curve the square of whose radius vector varies inversely as the angle which the radius vector makes with a given line.

alpenhorn alphorn alto horn ballad horn baritone bass horn brass choir brass wind brass-wind instrument brasses bugle bugle horn clarion cornet cornet-a-pistons corno di caccia cornopean double-bell euphonium euphonium helicon horn hunting horn key trumpet lituus lur mellophone ophicleide orchestral horn pocket trumpet post horn sackbut saxhorn saxtuba serpent slide trombone sliphorn sousaphone tenor tuba tromba trombone trumpet tuba valve trombone valve trumpet