一不小心 yī bù xiǎo xīn

DEFINITIONS

  1. carelessly; inadvertently; accidentally

CHARACTERS

一 yī
HSK 1
one; a, an; alone
不 bù
HSK 1
no, not; un-; negative prefix
小 xiǎo
HSK 1
small, tiny, insignificant
心 xīn
HSK 3
heart; mind, intelligence; soul