(literary, with "the") The deep part of a lake, sea, etc.

(with "the") The sea, the ocean.

A deep hole or pit, a water well; an abyss.

(literary, with "the") A silent time; quiet isolation.

(rare) A deep shade of colour.

(US, rare) The profound part of a problem.

(cricket) A fielding position near the boundary.

(of distance or position; also figurative) An adjective "deep" is used to describe something that extends far away from a point of reference, especially downwards, but can also refer to extent in other directions, thickness, volume, or being positioned far down or into something.

(intellectual, social) Complex, profound, significant, hard to comprehend, and represents penetrating intellect.

(sound, voice) Low in pitch.

(of a color or flavour) Highly saturated; rich.

(sleep) Sound, heavy (describing a state of sleep from which one is not easily awoken).

Muddy; boggy; sandy; said of roads.

(of time) Distant in the past, ancient.

Far, especially far down through something or into something, physically or figuratively.

(also deeply) In a profound, not superficial, manner.

(also deeply) In large volume.

(sports) Back towards one's own goal, baseline, or similar.