The term "in-variable" refers to the quality of being unable to change or vary. When we consider antonyms to this term, we can think of words that imply change, variation, adaptability, or unpredictability. Some examples of words that might be antonyms for "in-variable" include "mutable," "adaptable," "flexible," "spontaneous," "fluctuating," "varying," "changeable," and "unpredictable." Each of these words conveys a sense of variation, either in terms of a specific quality or overall behavior. While "in-variable" suggests something that is fixed or unchangeable, these antonyms suggest that change, variation, or adaptability are present.