from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Beyond question or doubt. See Synonyms at authentic.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. undeniable, obvious
from the GNU version of the Collaborative International Dictionary of English
- adj. Not questionable.
- adj. Not inviting questions or conversation.
from The Century Dictionary and Cyclopedia
- That cannot be questioned or doubted; indubitable; certain: as, unquestionable evidence or truth; unquestionable courage.
- Averse to being questioned; averse to conversation.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. incapable of being questioned
- adj. not open to question
- adj. not counterfeit or copied
un- + question + -able (Wiktionary)