abyss

the ocean's abysses大洋深处

I stood at the edge of the cliff and gazed down into the yawning/gaping abyss. [=chasm]我站在悬崖边缘，凝望着下面见不到底的深渊。

He says that there is a widening abyss between the rich and the poor.他说贫富之间的差距正在拉大。

She was pulled down into an abyss of despair.她坠入了绝望的深渊。