1Usually in plural Either of the horns on the head of the Devil or a devil; a model or representation of this, especially worn as an item of fancy dress.
2In plural A hand gesture representing devil's horns, made by extending the index and little fingers while holding the middle and ring fingers down with the thumb.
3British, East Anglian English dialect, historical, rare The stinkhorn fungus Phallus impudicus. Also "devil's horn fungus".
Late 16th century. From the genitive of devil + horn.