몰래 + verb; noun + 몰래 (부모님 몰래)
secretly, in secret, without telling
Example
동생이 엄마 몰래 과자를 먹었어요.
My little sister ate snacks without Mom knowing.
Word parts
Related to 모르다 'not to know': done so others won't know.
Good to know
Put a person before it to mean 'behind their back': 선생님 몰래.
Related words