Pulling In Their Horns

To pull in your horns is to calm down, and to lower your ambitions. You may think this colloquialism began with bulls, but that’s actually not the case, according to The Phrase Finder… You might think that warning someone who had overreached themselves in some dynamic enterprise to ‘pull their horns in’ was a reference to some pugnacious horned creature, maybe a bull or a rhinoceros. In fact, the c...

source https://thereformedbroker.com/2019/01/22/pulling-in-their-horns/