invariable

Not changing or subject to change; constant.

Not variable; constant; uniform; unchanging.

Not capable of being varied; unalterable; unchangeable.

In mathematics, a quantity that does not vary; a constant.

Not given to variation or change; unalterable; unchangeable; always uniform.

An invariable quantity; a constant.

Not variable; that always has the same value in different occurrences.

constant.

That cannot undergo inflection, conjugation or declension.

Something that does not vary; a constant.