In biblical and derived uses a horn is taken as an emblem of power and might, a means of defence or resistance.
In Christian iconography (except as in the horns of Moses), the representation of horns on the head of a person or supernatural being are a sign of evil. Horns were also fancifully said to be worn by a cuckold.
Recorded from Old English and of Germanic origin, the word comes from an Indo-European root shared by Latin cornu and Greek keras.
horn of plenty another name for a cornucopia.
See also gate of horn, horns, make a spoon or spoil a horn.