匪

Bandits, robbers, rebels, or gangsters. Related to 賊 and 寇.

Functions as a negative particle (interchangeable with 非 or 不), acting as an adverbial negation of verbs or adjectives. Often appears in poetic or ritual registers; may carry more emphatic weight than 不.

In early texts, the choice between 匪 and 非 is often a matter of register or meter rather than a difference in basic meaning.

The Tang reading (piə̌i) and Fanqie (府尾) suggest phonetic proximity between the nominal "bandit" sense and the negative particle function in early Chinese.

If the syntax suggests a predicate rather than a noun, treat this as "not" or "do not."