horn

1 horn /ˈhoɚn/ noun
plural horns
1 horn
/ˈhoɚn/
noun
plural horns
Britannica Dictionary definition of HORN
1 
a  [count] : one of the hard pointed parts that grows on the head of some animals (such as cattle, goats, or sheep)
b  [count] : a hard pointed part that grows on the nose of a rhinoceros
c  [noncount] : the hard material of which horns are made
2 
[count] : something that is shaped like a horn
3 
[count]
a  : a brass musical instrument (such as a trumpet or trombone) — see also english horn, french horn
b  : an instrument made from an animal's horn that is used for music or for producing loud signals
4 
[count] : a device that makes a loud noise
— see picture at car
5 
the horn US slang : 1telephone

blow your own horn

US, informal or toot your own horn
: to talk about yourself or your achievements especially in a way that shows that you are proud or too proud

lock horns

— see 2lock

on the horns of a dilemma

: in a situation in which you have to choose between things that are unpleasant or undesirable

pull in your horns

also draw in your horns
: to begin to behave in a more careful way
especially : to spend or invest money more carefully

take the bull by the horns

— see 1bull

— hornless

/ˈhoɚnləs/ adjective
2 horn /ˈhoɚn/ verb
horns; horned; horning
2 horn
/ˈhoɚn/
verb
horns; horned; horning
Britannica Dictionary definition of HORN

horn in

[phrasal verb] US, informal + usually disapproving
: to add your comment or opinion to a conversation or discussion that you have been listening to — usually + on