in ‧ sol ‧ u ‧ ble /ɪnˈsɒljəb ə l, ɪnˈsɒljʊb ə l $ ɪnˈsɑːl-/ BrE AmE adjective
[ Word Family: noun : ↑ solution , ↑ solvent , ↑ solubility , ↑ insolvency ; adjective : ↑ soluble ≠ ↑ insoluble , ↑ unsolved , ↑ solvent ≠ ↑ insolvent , ↑ solvable ≠ ↑ insolvable ; verb : ↑ solve ; adverb : ↑ insolvably ]
1 . an insoluble problem is or seems impossible to solve:
insoluble conflicts within the department
2 . an insoluble substance does not become a liquid when you put it into a liquid OPP soluble ⇨ dissolve