Definition
乘虚而入 is a four-character idiom (成语) meaning 'to exploit an opponent's weakness or moment of vulnerability.' It originates from military strategy—attacking when the enemy is off guard—but is now used in many competitive contexts (business, debate, games, etc.). The literal breakdown ('ride on emptiness and enter') won't help you guess the meaning, so remember the core idea: seizing the chance when the other side's defenses are down.
f.e.
to exploit an opponent's weakness or moment of vulnerabilityto seize an opportunity to attack when the other side is off guard
Examples
- ，乘虚而入，。Dírén fángshǒu sōngxiè shí, wǒ jūn chéng xū ér rù, yìjǔ gōngzhàn le zhèndì.When the enemy's defense was lax, our army exploited their weakness and captured the position in one stroke.
- 乘虚而入，。Zhè jiā gōngsī chènzhe duìshǒu zījīn kùnnán shí chéng xū ér rù, qiǎng zǒu le hěn duō kèhù.This company took advantage of its competitor's financial difficulties and snatched away many clients.
- ，乘虚而入，。Lǎoshī zhuǎnshēn xiě zì shí, yǒu tóngxué chéng xū ér rù, tōutōu chī le língshí.When the teacher turned around to write on the board, some student took the chance to secretly eat a snack.
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