I. (ˈ)in, ən+ adjective
Etymology: alteration (influenced by Latin insolubilis ) of Middle English insolible, from Latin insolubilis, from in- in- (I) + solvere to free, dissolve + -bilis -able — more at solve
: not soluble: as
a. archaic : incapable of being loosened : indissoluble
b. : having or admitting of no solution or explanation : unsolvable
an insoluble doubt
c. obsolete , of an argument : unanswerable , irrefutable
d. : incapable of being dissolved in a liquid
chalk is insoluble in water
broadly : soluble only with difficulty or to a slight degree
a very insoluble salt, dissolving no more than 1 part in 500,000 of water
• in·solubleness “+ noun
• in·solu·bly “+ adverb
II. noun
Etymology: alteration (influenced by Latin insolubilis, adjective) of Middle English insolible, from insolible, adjective
1. : something (as a problem or difficulty) that cannot be solved
2. : an insoluble substance
the insolubles in a tanning extract