insoluble

1. ADJ An insoluble problem is so difficult that it is impossible to solve. 不能解决的

I pushed the problem aside; at present it was insoluble. 我把这个问题放到了一边；目前它是无法解决的。

2. ADJ If a substance is insoluble, it does not dissolve in a liquid. 不溶解的

Carotenes are insoluble in water and soluble in oils and fats. 胡萝卜素不溶于水，但溶于油和脂肪。