The word "most aeronautical" refers to objects or activities that involve or pertain to the science of flight. Antonyms for this word may include terrestrial, ground-bound, stationary, or non-aerodynamic. Examples of non-aeronautical objects or activities could be cars, trains, bicycles, hiking, or swimming. In other words, the antonyms for "most aeronautical" would be anything not related to flying or aviation. While aviation plays a vital role in transportation and travel, there are various other modes of transportation and activities that people enjoy on the ground, in the water, or elsewhere.