adj.
1 ( esp. BrE ) ( AmE usually insolvable ) that cannot be solved/explained
VERBS
▪ be , seem
▪
The problem seemed ~.
▪ remain
ADVERB
▪ almost
▪ apparently , seemingly
2 impossible to dissolve in a liquid
VERBS
▪ be
ADVERB
▪ highly
▪ relatively
▪ almost , practically , virtually
PREPOSITION
▪ in
▪
These chemicals are practically ~ in water.
Insoluble is used with these nouns: ↑ mystery , ↑ problem