乘虚

乘虛
chéngxū
to take advantage of weakness

CEDICT

to act when somebody is off guard

Wiktionary

  1. 凌空、腾空。
  2. 趁人不备或守备空虚的时候。

重編國語辭典

Entry Composition

=1 乘 chéng
  1. to ride
  2. to mount
  3. to make use of
  4. to avail oneself of
  5. to take advantage of
  6. to multiply (math.)
  7. Buddhist sect or creed
=1 乘 chéng old variant of 乘 chéng
2 虚 xū
  1. emptiness
  2. void
  3. abstract theory or guiding principles
  4. empty or unoccupied
  5. diffident or timid
  6. false
  7. humble or modest
  8. (of health) weak
  9. virtual
  10. in vain

Containing this entry

乘虚而入 chéngxūérrù to enter by exploiting a weak spot (idiom); to take advantage of a lapse
乘虚而入 chéngxū'érrù