This is the 2161st most frequent Korean word.
입을
The Korean word "입을" means "mouth" (object form) or refers to "wear" (as in clothing, depending on context).
In this sentence, '입을' refers to 'mouth', emphasizing the act of speaking.
그는 입을 열어서 진실을 말했다.
He opened his mouth and told the truth.
Here, '입을' means 'to wear', as in putting on formal attire.
나는 내일 중요한 회의가 있어서 정장을 입을 거예요.
I will wear a suit tomorrow because I have an important meeting.
In this context, '입을' indicates to don or put on clothing, referring to an imaginary scene.