The term "are constituent" refers to things that are made up of parts or components. Antonyms for this phrase may include "are non-constituent" or "are homogeneous." When something is non-constituent, it is not composed of distinct parts or elements. Homogeneous, on the other hand, means that something is uniform or composed of the same substance throughout. Other antonyms for "are constituent" may include terms such as "are singular" or "are monolithic," which indicate something that is undivided or not made up of different parts. These antonyms can be useful in describing the characteristics of various objects or materials.