insoluble

adjective

in·​sol·​u·​ble (ˌ)in-ˈsäl-yə-bəl 

: not soluble: such as

a

: incapable of being dissolved in a liquid and especially water

also : soluble only with difficulty or to a slight degree

b

: having or admitting of no solution or explanation

an insoluble problem

c

archaic : indissoluble

insolubility

(ˌ)in-ˌsäl-yə-ˈbi-lə-tē 

noun

insoluble noun

insolubleness

(ˌ)in-ˈsäl-yə-bəl-nəs 

noun

insolubly

(ˌ)in-ˈsäl-yə-blē 

adverb

Synonyms

• hopeless
• impossible
• insolvable
• insuperable
• unattainable
• undoable
• unrealizable
• unsolvable

Examples of insoluble in a Sentence

a substance insoluble in water

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

Recent Examples on the Web

Bacteria in the gut do not ferment (break down) insoluble fiber.1 Soluble fiber ferments in the gut, which releases helpful by-products such as short-chain fatty acids (SCFAs).1 SCFAs have health-promoting effects, including fighting inflammation and supporting the immune system.2 1. —Johna Burdeos, Health, 4 Dec. 2024

Yet the dilemmas posed by partition long predate 1967 and stem from a fundamentally insoluble problem. —Yousef Munayyer, Foreign Affairs, 15 Oct. 2019

Many plant foods contain both soluble and insoluble fiber, but certain grains, like oats and barley, as well as beans, fruits, and vegetables, are particularly rich in soluble fiber. —Johna Burdeos, Health, 4 Dec. 2024

In addition, zucchini is a good source of insoluble and soluble fiber, which helps stabilize blood sugar and decrease the risk of heart disease. —Bethany Thayer, Detroit Free Press, 28 Sep. 2024

Word History

Etymology

Middle English insolible, from Latin insolubilis, from in- + solvere to free, dissolve — more at solve

First Known Use

14th century, in the meaning defined above

Kids Definition

insoluble

adjective

in·​sol·​u·​ble (ˈ)in-ˈsäl-yə-bəl 

1

: impossible to solve

an insoluble problem

2

: impossible or difficult to dissolve

a substance insoluble in water

Medical Definition

insoluble

adjective

in·​sol·​u·​ble (ˈ)in-ˈsäl-yə-bəl 

: incapable of being dissolved in a liquid

also : soluble only with difficulty or to a slight degree