Antonyms for the word "makes consistent" include "varies," "inconsistent," "irregular," "unpredictable," and "unreliable." When an action, behavior, or outcome is "varies," it means that it is different or changes depending on different factors. "Inconsistent" implies that an action, behavior, or outcome is not consistent and may vary from time to time. "Irregular" suggests that something is not regular, that is, there is no pattern or sequence. "Unpredictable" signifies that something is not predictable, and one cannot anticipate what will happen. Finally, "unreliable" means that something or someone is not dependable or trustworthy.