bù​xuān'ér​zhàn

to start an undeclared war

不宣而战 不宣而戰 bù​xuān'ér​zhàn
to start an undeclared war
To open hostilities or launch an attack without a formal declaration
to engage in unfair competition
To attack a competitor using underhanded means or without prior warning, such as a surprise price cut

Frequency

Written text
0.085 per million

Sources

Frequency data
BCC Corpus (BLCU)