Invariable
Part of speech: adjective
Definition: not variable
Constant
Part of speech: adjective
Definition: Unchanged through time or space; permanent.Consistently recurring over time; persistentSteady in purpose, action, feeling, etc.
Part of speech: noun
Definition: That which is permanent or invariable.A quantity that remains at a fixed value throughout a given discussion.Any property of an experiment, determined numerically, that does not change under given circumstances.An identifier that is bound to an invariant value.
Example sentence: If a man does not make new acquaintances as he advances through life, he will soon find himself left alone. A man, sir, should keep his friendship in a constant repair.