From Longman Dictionary of Contemporary Englishldoce_162_bhornhorn1 /hɔːn $ hɔːrn/ ●●○ noun 1 
animal a) [countable] the hard pointed thing that grows, usually in pairs, on the heads of animals such as cows and goats → antlers b) [uncountable] the substance that animals’ horns are made of a knife with a horn handle c) [countable] a part of an animal’s head that sticks out like a horn, for example on a snail2 on a car [countable]TMC the thing in a vehicle that you use to make a loud sound as a signal or warningsound/toot/honk/blow your horn (=make a noise with your horn)3 musical instrument [countable] a) APMa musical instrument like a long metal tube that is wide at one end, that you play by blowing b) informal a trumpet c) a French horn d) APMa musical instrument made from an animal’s horn → English horn4 → drinking horn/powder horn etc5 → draw/pull in your horns6 → be on the horns of a dilemma → blow your own trumpet/horn at blow1(19), → lock horns at lock1(7), → take the bull by the horns at bull1(3)
animal a) [countable] the hard pointed thing that grows, usually in pairs, on the heads of animals such as cows and goats → antlers b) [uncountable] the substance that animals’ horns are made of a knife with a horn handle c) [countable] a part of an animal’s head that sticks out like a horn, for example on a snail2 on a car [countable]TMC the thing in a vehicle that you use to make a loud sound as a signal or warningsound/toot/honk/blow your horn (=make a noise with your horn)3 musical instrument [countable] a) APMa musical instrument like a long metal tube that is wide at one end, that you play by blowing b) informal a trumpet c) a French horn d) APMa musical instrument made from an animal’s horn → English horn4 → drinking horn/powder horn etc5 → draw/pull in your horns6 → be on the horns of a dilemma → blow your own trumpet/horn at blow1(19), → lock horns at lock1(7), → take the bull by the horns at bull1(3)Examples from the Corpus
horn• horn-rimmed glasses• He contrasted sharply with the acceptance horn, exemplified by career policemen.• We will therefore use the four horns in unison.• The driver leaned out of the window and shouted at the lad, sounded his horn twice, then drove on.• The palace enhances this quality through its long flat courtyard, which leads us directly to the rising horns.• When you blow the horn, it sounds blaring.sound/toot/honk/blow your horn• As she turned uphill, a dark-red Daimler slid by, and blew its horn at her.• Motorists below honked their horns and flashed their headlights in response.• The driver sounded his horn furiously as the taxi sped on.• For the remainder of the evening, Barbara and A. B. Everage honked their horn and flashed their lights.• Nanny hoisted her higher in her arms as the huntsman blew his horn and the hounds moved off.• Other angry motorists blew their horns and flashed rude two-finger salutes when they finally managed to overtake him.• Dilip drove off honking his horn and threatening to run down those who were slow to get out of his way.• Fire trucks honked their horns, beer was sprayed on bar patrons and bikini-clad women kissed strangers.hornhorn2 verb → horn in→ See Verb tableExamples from the Corpus
horn• For a while, being there felt like horning in on a family reunion.Horn, thethe HornHorn, the → see Cape HornOrigin horn1 Old English 