Exact Match:
- inconvertible
- not capable of being changed into something else; "the alchemists were unable to accept the inconvertible nature of elemental metals"
- used especially of currencies; incapable of being exchanged for or replaced by another currency of equal value
Synonyms:
- changeless,
- constant,
- immutable,
- incommutable,
- indefeasible,
- inert,
- insusceptible of change,
- intransmutable,
- invariable,
- irredeemable,
- irretrievable,
- irreversible,
- irrevocable,
- lasting,
- noble,
- nonreturnable,
- nonreversible,
- permanent,
- reverseless,
- unalterable,
- unalterative,
- unaltered,
- unchangeable,
- unchanged,
- unchanging,
- undeflectable,
- undeviating,
- unmodifiable,
- unpayable,
- unremitting,
- unrestorable,
- unreturnable,
- unsusceptible,
- unvariable,
- unvarying