Most coextensive is a term used to describe two or more things that are of equal length or size. Antonyms for most coextensive include words such as unequal, asymmetrical, disproportionate, and dissimilar. These words indicate that two or more things are not the same in size, shape, or length, and have differences to them. For example, an unequal relationship means that one person or thing is in a more powerful position than the other. Asymmetrical means that two things are not identical, and disproportionate means that two things are not in the same proportion to each other. In short, antonyms for most coextensive indicate a lack of equality between two or more things.