/inˈsälyəbəl/
Adjective
1. That cannot be dissolved. (wiktionary.org)
2. That cannot be solved; insolvable. (wiktionary.org)
3. That cannot be explained; mysterious or inexplicable. (wiktionary.org)
Word origin: From Latin insolubilis “that cannot be loosened,” from in– “not” + solubilis “soluble”