| Insoluble 1. (a.) Not soluble; in capable or difficult of being dissolved, as by a liquid; as, chalk is insoluble in water. 2. (a.) Not to be solved or explained; insolvable; as, an insoluble doubt, question, or difficulty. 3. (a.) Strong. Thesaurus Entries coherent, cohesive, enwrapped in mystery, impartible, indefinable, indiscerptible, indissoluble, indissolvable, indivisible, inexplicable, inextricable, infrangible, infusible, inseparable, insolvable, mysterious, mystic, unaccountable, undefinable, undividable, unexplainable, unified, uninterpretable, unsolvable |