unchallengeable
unc·hal·len·geable
adjective
1.
- “unchallengeable facts”
- “a position of unchallengeable supremacy”
Origin
From un- + challengeable.
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.