The word 凭空 is formed by combining the character 凭, meaning "to rely on" or "on the basis of", with 空, meaning "empty" or "void". Literally, it conveys the idea of "leaning on emptiness" or "based on nothing". This figurative compound describes an action or statement that is fabricated without any factual evidence, foundation, or substantiation, such as an unfounded rumor, a baseless accusation, or pure imagination, often seen in phrases like 凭空想象 (to imagine out of thin air) or 凭空捏造 (to fabricate without evidence).