This is the 2826th most frequent Korean word.
입
"입" means "mouth" in English.
Here, '입' is used literally to signify the physical mouth of the baby.
아기가 입을 크게 벌리고 울었다.
The baby opened his mouth wide and cried.
In this sentence, '입' refers to the figurative speech or expression related to the mouth.
그의 입에서 거짓말이 나왔다.
A lie came out of his mouth.
In this example, '입' implies the action of closing the mouth, denoting remaining silent.