약속이 · 약속을
promise; appointment, plans (to meet)
Example
오늘 저녁에 친구하고 약속이 있어요.
I have plans with a friend this evening.
Word parts
약 agree+속 bind
Literally 'agree and tie down'.
Good to know
약속 covers both 'promise' and 'plans to meet someone'. Pronounced [약쏙].
Related words