Synonyms of the word

changeless

• adj. unchanging.

constant

• adj. Unchanged through time or space; permanent.
• adj. Consistently recurring over time; persistent.
• adj. Steady in purpose, action, feeling, etc.
• adj. Firm; solid; not fluid.
• adj. (obsolete) Consistent; logical.
• n. That which is permanent or invariable.
• n. (algebra) A quantity that remains at a fixed value throughout a given discussion.
• n. (sciences) Any property of an experiment, determined numerically, that does not change under given circumstances.
• n. (computing) An identifier that is bound to an invariant value; a fixed value given a name to aid in readability…

immutable

• adj. Unable to be changed without exception.
• adj. (programming, of a variable) Not able to be altered in the memory after its value is set initially, such…
• n. Something that cannot be changed.

invariable

• adj. Not variable; unalterable; uniform; always having the same value.
• adj. (mathematics) Constant.
• adj. (by extension, grammar, of a word, or a grammatical class) That cannot undergo inflection, conjugation…
• n. Something that does not vary; a constant.

invariant

• adj. not varying; constant.
• adj. (mathematics) Unaffected by a specified operation (especially by a transformation).
• adj. (computing, programming) Neither covariant nor contravariant.
• n. An invariant quantity, function etc.

unalterable

• adj. incapable of changing or being altered.
• adj. irrevocable or irreversible.

unchangeable

• adj. Not changeable; incapable of being changed or of changing; immutable.
• n. Something that cannot be changed.

unvarying

• adj. persistent, constant or changeless.
• adj. lacking variety; having a uniform character.