Go air is a phrase that generally refers to flying or traveling by air. When looking for synonyms for this phrase, the most obvious choice is "fly," which means to move through the air with wings or using some other form of propulsion. Other synonyms include "travel by plane," "take a flight," "take to the sky", "jet off" and "board a plane". All of these options can be used to convey a similar meaning to "go air," but each one may carry a slightly different connotation. Ultimately, the choice of synonym will depend on the context in which it is being used and the desired tone or emphasis of the statement.