insoluble
adj.adj. describing a problem or situation that cannot be fixed or explained. It also describes a substance that cannot be dissolved in a liquid.
adj. incapable of being solved, explained, or dissolved in a particular solvent. Often used to describe complex or persistent problems that defy resolution.
The two companies have an insoluble problem.
The scientist discovered that the new polymer was insoluble in water, making it difficult to clean up.
The conflict between the two nations reached an insoluble point, as neither side was willing to compromise on its core territorial claims.
From Middle English insolible, from Middle French insoluble, from Latin insolūbilis, from in- + solūbilis. Piecewise doublet of insolvable and unsolvable. By surface analysis, in- + soluble.