Spend air is an idiomatic expression used to convey the notion of wasting time or engaging in unproductive activities. Synonyms for spend air include "idle away", "fritter away" or "squander". These words express the idea of using time in a frivolous or aimless manner. Additionally, "waste", "misspend" or "consume" can also be used as alternatives to spend air. However, they emphasize the squandering aspect rather than the concept of time itself. Whether someone spends air chatting mindlessly or procrastinating instead of being productive, there are various synonyms available to describe this unproductive behavior.