The antonyms for the word "airconditioned" are numerous, but all have the same basic meaning: a lack of air conditioning. Some possible antonyms include sweltering, humid, oppressive, muggy, stifling, and suffocating. Other antonyms might include words like unventilated, uncooled, hot, stuffy, and steamy. All of these words suggest a discomforting lack of cooling air, and they can be used to describe anything from a small room to an entire building or region. When describing a space or place that is not air-conditioned, it is important to be precise in your language to accurately convey the level of discomfort experienced.