opaque /əuˈpeik/ adj. 1. 不透明的；不传热的：The once clear mountain stream is now polluted and opaque.曾经是很清澈的山溪, 现在受到污染变得混浊了。2. 难理解的，晦涩的：The report was written in long, opaque sentences.报告中的句子又长又难懂。