Meaning of “horn” - Learner’s Dictionary

horn

noun [ C ] uk us /hɔːn/
ANIMAL

one of the two hard, pointed growths on the heads of cows, goats, and some other animals

EQUIPMENT

B2 a piece of equipment used to make a loud sound as a warning or signal:

a car horn
The taxi driver hooted his horn.
MUSIC

a curved musical instrument that you blow into to make a sound:

the French horn

(Definition of “horn” from the Cambridge Learner’s Dictionary © Cambridge University Press)