The most common Korean word for “sleep” is 자다 (jada). There are 3 more words with a similar meaning — compare them below. 「sleep」는 한국어로 자다.
to sleep
TOPIK 1 · verb · honorific: 주무시다
sleep
TOPIK 1 · noun
sleep (honorific)
TOPIK 1 · verb · honorific form of 자다 — use it for elders and customers
Words and levels: TOPIK I essentials (National Institute of Korean Language standard curriculum, KOGL Type 1) · examples: Cheesepotato