adjective
(of distance or position; also figurative) Extending, reaching or positioned far from a point of reference, especially downwards.
(intellectual, social) Complex, involved.
(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.
adverb
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.
noun
(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.
A deep or innermost part of something in general.
(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.
verb
(slang, MLE, transitive) To overthink; to treat as being deeper (“more profound, significant”) than in reality.
(slang, MLE, transitive) To think about, especially deeply (“profoundly”); to consider.