In*sol"u*ble (?), a. [L. insolubilis indissoluble, that can not be loosed: cf. F. insoluble. See In- not, and Soluble, and cf. Insolvable.]
1.
Not soluble; in capable or difficult of being dissolved, as by a liquid; as, chalk is insoluble in water.
2.
Not to be solved or explained; insolvable; as, an insoluble doubt, question, or difficulty.
3.
Strong.
"An
insoluble wall." [Obs.]
Holland
© Webster 1913.