unsoluble
un·so·luble
adjective
1.
- “an apparantly insolvable problem”
- “public finance...had long presented problems unsolvable or at least unsolved” C.L.Jones
Origin
From un- + soluble.
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.