Synonyms of insoluble

insoluble

adjective

(ˌ)in-ˈsäl-yə-bəl 

as in impossible

incapable of being solved or accomplished

the seemingly insoluble mystery concerning the identity of the people who built these ancient structures

Synonyms & Similar Words

• impossible
• hopeless
• problematical
• unlikely
• problematic
• insolvable
• unsolvable
• insuperable
• futile
• unattainable
• impractical
• unrealizable
• undoable
• useless
• incredible
• unworkable
• impracticable
• absurd
• unusable
• questionable
• infeasible
• dubious
• improbable
• suspect
• inconceivable
• debatable
• unfeasible
• disputable
• suspicious
• implausible
• fishy
• unthinkable
• fantastical
• shaky
• unimaginable
• unbelievable
• doubtful
• ridiculous
• far-fetched
• doubtable
• outlandish
• shady
• preposterous
• fantastic

Antonyms & Near Antonyms

• soluble
• possible
• feasible
• workable
• practical
• achievable
• attainable
• useful
• applicable
• functional
• reasonable
• usable
• resolvable
• practicable
• working
• probable
• realizable
• serviceable
• likely
• doable
• useable
• acceptable
• plausible
• conceivable
• credible
• believable

Example Sentences

Recent Examples of insoluble

Black beans are also high in soluble and insoluble fiber.14 Fiber is needed for digestive and cardiovascular health. —Maxine Lipner, Verywell Health, 12 Mar. 2025

And in people whose IBS manifests as constipation (IBS-C), insoluble fibers like wheat bran could help get things going and alleviate symptoms. —Erica Sloan, SELF, 19 Feb. 2025

Soluble and insoluble fibers help promote regular bowel movements. —Larell Scardelli, Verywell Health, 5 Mar. 2025

That's because fiber-rich foods naturally tend to have a mix of multiple fibers, which can be categorized into two types: soluble and insoluble. —Erica Sloan, SELF, 19 Feb. 2025