1. n. [Geology]

The deepest area of the ocean basins. The depositional energy is low and fine-grained sediments are deposited slowly by waning turbidity currents or from suspension in the water. The water is thousands of meters deep (>2,000 m) [>6,520 ft] so it is cold and sunlight is minimal.

See: abyssal,  bathyal,  benthic,  depositional energy,  littoral,  neritic,  turbidite,  turbidity current