"Drink air" is a phrase that means to take a sip of a beverage, but without actually consuming any liquid. It's a colloquialism often used as a joke or exaggeration. While there are no direct synonyms for this phrase, there are similar idiomatic expressions that convey the same meaning in different words. For instance, "sip at an empty cup," "raise an empty glass," or "take a swig of nothing" all suggest the act of drinking without any actual liquid present. These expressions are less commonly used than "drink air," but they serve the same purpose of highlighting an empty or non-existent drink.