Proto-Korean: *čá(ŋ)-
Meaning: to sleep
Russian meaning: спать
Modern Korean: ča-, ča-si-, čumu-si-
Middle Korean: ča-, čá-sì-, ča'ăp-so-
Comments: Nam 411, KED 1374, 1380, 1497. The modern honorific čumu-si- is probably < *čaŋwu-si- ~ *čaŋup-si- = MKor. ča'ăp-so-.