[mass noun]the condition of lacking transparency or translucence 不透明;半透明 thinner paints need black added to increase opacity. 薄的画需要加点黑色来减少透明度。 ■(figurative)obscurity of meaning (喻)晦涩;难解 the difficulty and opacity in Barthes' texts. 巴尔瑟斯作品的难度和晦涩。
语源
mid 16th cent.: from French opacité, from Latin opacitas, from opacus 'darkened'