from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Impossible to dispute or disprove; undeniable: unassailable truths.
- adj. Not subject to attack or seizure; impregnable: an unassailable fortress.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. secure against attack; impregnable
- adj. undeniable, incontestable or incontrovertible
from The Century Dictionary and Cyclopedia
- Not assailable; incapable of being assailed; incontestable; hence, not to be moved or shaken from a purpose.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. impossible to assail
- adj. without flaws or loopholes
- adj. immune to attack; incapable of being tampered with
un- + assailable (Wiktionary)