The antonyms for the phrase "am on air" are primarily related to being off air or disconnected. Some common antonyms include "off the air," "disconnected," "down," "off-line," "idle," and "out of service." When someone is off the air, they are not broadcasting or transmitting any signals. It could be due to technical difficulties or simply because they have not started their broadcast yet. Being disconnected or off-line means that there is no connection or communication taking place. These antonyms are important to understand in the context of broadcasting or communication channels, as they indicate when the transmission is no longer active or functional.