The word 久等 is formed by directly combining the independent concept of "久" (jiǔ), meaning "a long duration of time", with the action "等" (děng), meaning "to wait". This fusion does not follow a syntactic rule but rather creates a compact, figurative unit where the modifier "久" vividly describes the state or experience of the action "等". The result is a seamless conceptual blend that immediately evokes the specific scenario of an extended or protracted wait, often used as a polite social acknowledgment of that situation.