from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Impossible to alter: the unalterable season of bitter cold in Siberia.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. incapable of changing or being altered
- adj. irrevocable or irreversible
from The Century Dictionary and Cyclopedia
- Not alterable; unchangeable; immutable.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. of a sentence; that cannot be changed
- adj. not capable of being changed or altered
- adj. remaining the same for indefinitely long times
un- + alterable (Wiktionary)