insoluble adj.
1 that cannot be solved/explained
VERBS be, seem | remain
ADV. absolutely | almost | apparently, seemingly
2 impossible to dissolve in a liquid
VERBS be
ADV. highly | practically, virtually
PREP. ~ in These chemicals are practically insoluble in water.
You can also check other dicts: insoluble (English, 中文解释 ), wordnet sense, Collins Definition