不由自主 bù yóu zì zhǔ

DEFINITIONS

  1. can't help; involuntarily (idiom)

CHARACTERS

不 bù
HSK 1
no, not; un-; negative prefix
由 yóu
HSK 4
cause, reason; from
自 zì
HSK 3
self, private, personal; from
主 zhǔ
HSK 3
master, chief owner; host; lord