Idioms of horn in English

blow/toot your own horn (North American English) (also blow your own trumpet especially in British English)

(informal) to praise your own abilities and achievements

draw/pull your horns in

to start being more careful in your behaviour, especially by spending less money than before

Small businesses have had to pull their horns in during the recession.

lock horns (with somebody) (over something)

to get involved in an argument with somebody

The company has locked horns with the unions over proposed pay cuts.

on the horns of a dilemma

in a situation in which you have to make a choice between things that are equally unpleasant

The medical profession’s eagerness for scientific advance had impaled it on the horns of a dilemma, forcing an unnatural choice between science and morality.

The dire economic situation had placed the prime minister on the horns of a dilemma.

take the bull by the horns

to face a difficult or dangerous situation directly and with courage

Nora decided to take the bull by the horns and organize things for herself.