constant vs invariant

constant and invariant both are nouns.

Word	Noun	Adjective	Verb	Adverb
constant	Yes	Yes	No	No
invariant	Yes	Yes	No	No

As adjectives, constant and invariant are synonyms defined as:

Other synonyms of constant include changeless, unvarying.

constant (noun)	invariant (noun)
a quantity that does not vary	a feature (quantity or property or function) that remains unchanged when a particular transformation is applied to it
a number representing a quantity assumed to have a fixed value in a specified mathematical context

constant (adjective)	invariant (adjective)
steadfast in purpose or devotion or affection	unvarying in nature
uninterrupted in time and indefinitely long continuing	unaffected by a designated operation or transformation
unvarying in nature