The phrase "put on air" refers to the act of broadcasting or airing a program, show, or content on television, radio, or other media platforms. The biggest antonym for "put on air" is "take off air," which means to cancel or remove a program from broadcasting. Another antonym for "put on air" could be "suppress," which means to prevent something from being aired or published. Additionally, "conceal," "hide," and "secrete" can also be antonyms for "put on air," as they all imply an act of withholding information or content from the public. Overall, there are several antonyms for "put on air" that suggest either the removal or withholding of content.