The term "invariant" refers to something that does not change or remain constant regardless of varying conditions. Synonyms for this word include unchanging, fixed, steadfast, consistent, immutable, enduring, constant, and inviolate. Each of these words conveys a similar idea but may be used in different contexts. For example, "unchanging" and "fixed" may be used to describe an unalterable physical object, while "steady" and "consistent" may be used to describe a person's character or behavior. "Immutable" and "inviolate" are stronger synonyms that imply absolute and unbreakable permanence. Overall, these synonyms for the word "invariant" help to convey the idea of something that remains unchanged and dependable over time.