INVARIANT
changeless, constant, invariant, unvarying
(adjective) unvarying in nature; “maintained a constant temperature”; “principles of unvarying validity”
invariant
(adjective) unaffected by a designated operation or transformation
invariant
(noun) a feature (quantity or property or function) that remains unchanged when a particular transformation is applied to it
Source: WordNet® 3.1
Etymology
Adjective
invariant (comparative more invariant, superlative most invariant)
not varying; constant
(mathematics) Unaffected by a specified operation (especially by a transformation)
(computing, programming) Neither covariant nor contravariant.
Synonyms
• (not varying): invariable
Noun
invariant (plural invariants)
An invariant quantity, function etc.
Source: Wiktionary
In*va"ri*ant, n. (Math.)
Definition: An invariable quantity; specifically, a function of the
coefficients of one or more forms, which remains unaltered, when
these undergo suitable linear transformations. J. J. Sylvester.
Source: Webster’s Unabridged Dictionary 1913 Edition