The phrase "was air" can be replaced with various synonyms depending on the context of the sentence. For instance, instead of saying "the room was airless," one could say "the room was stuffy" or "the room lacked ventilation." In a different context, "was air" can be replaced with "was atmosphere." For instance, "the restaurant was air-conditioned" can be rephrased to "the restaurant was atmospherically controlled." Similarly, instead of saying "the atmosphere was electric," one could say "the air was charged." In summary, a range of synonyms can be used in place of "was air" depending on the intended meaning of the sentence.