The phrase "be in mid-air" conveys a sense of a suspended state, often used to describe objects, people, or animals in the air. Antonyms for this phrase could include "resting on the ground," "firmly planted," or "stationary." Other possible antonyms might include "grounded," "landed," or "settled." In contrast to the idea of being suspended, such words evoke a sense of stability and an absence of movement. Depending on the context, other antonyms might include "land-bound," "earthbound," or "fixed." Ultimately, understanding the antonyms of "be in mid-air" can help convey a feeling of groundedness and permanence.