deep
Americanadjective
-
deeper,
comparative
-
deepest
superlative
-
extending far down from the top or surface.
a deep well;
a deep valley.
- Antonyms:
- shallow
-
extending far in or back from the front or from an edge, surface, opening, etc., considered as the front.
a deep shelf.
-
extending far in width; broad.
deep lace;
a deep border.
-
ranging far from the earth and sun.
a deep space probe.
-
having a specified dimension in depth.
a tank 8 feet deep.
-
covered or immersed to a specified depth (often used in combination).
standing knee-deep in water.
-
having a specified width or number of items from front to back (often used in combination).
shelves that are 10 inches deep;
cars lined up at the entrance gates three-deep.
-
extending or cutting far down relative to the surface of a given object.
The knife made a deep scar in the table.
-
situated far down, in, or back.
deep below the surface;
deep in the woods.
-
reaching or advancing far down.
a deep dive.
- Antonyms:
- shallow
-
coming from far down.
a deep breath.
-
made with the body bent or lowered to a considerable degree.
a deep bow.
-
immersed or submerged in or heavily covered with (followed byin ).
a road deep in mud.
-
difficult to penetrate or understand; abstruse.
a deep allegory.
- Synonyms:
- obscure, mysterious, recondite
-
not superficial; profound.
deep thoughts.
-
grave or serious.
deep disgrace.
-
deep affections.
-
deep study.
-
great in measure; intense; extreme.
deep sorrow.
-
sound and heavy.
deep sleep.
-
(of colors) dark and vivid.
a deep red.
-
low in pitch, as sound, a voice, or the like.
deep, sonorous tones.
-
having penetrating intellectual powers.
a deep scholar.
- Synonyms:
- sagacious, shrewd, intelligent, wise
-
profoundly cunning or artful.
a deep and crafty scheme.
-
deep, dark secrets.
-
immersed or involved; enveloped.
a man deep in debt.
-
deep in thought.
-
Baseball. relatively far from home plate.
He hit the ball into deep center field.
-
Linguistics. belonging to an early stage in the transformational derivation of a sentence; belonging to the deep structure.
noun
-
the deep part of a body of water, especially an area of the ocean floor having a depth greater than 18,000 feet (5,400 meters).
-
a vast extent, as of space or time.
-
the part of greatest intensity, as of winter.
-
Nautical. any of the unmarked levels, one fathom apart, on a deep-sea lead line.
-
Chiefly Literary. the deep, the sea or ocean.
He was laid to rest in the deep.
adverb
-
to or at a considerable or specified depth.
The boat rode deep in the water.
-
far on in time.
He claimed he could see deep into the future.
-
Baseball. at or to a deep place or position.
The outfielders played deep, knowing the batter's reputation as a slugger.
idioms
-
in deep,
-
inextricably involved.
-
having made or committed oneself to make a large financial investment.
-
-
go off the deep end,
-
to enter upon a course of action with heedless or irresponsible indifference to consequences.
-
to become emotionally overwrought.
-
-
in deep water,
-
in difficult or serious circumstances; in trouble.
-
in a situation beyond the range of one's capability or skill.
You're a good student, but you'll be in deep water in medical school.
-
adjective
-
extending or situated relatively far down from a surface
a deep pool
-
extending or situated relatively far inwards, backwards, or sideways
a deep border of trees
-
cricket relatively far from the pitch
the deep field
deep third man
-
-
(postpositive) of a specified dimension downwards, inwards, or backwards
six feet deep
-
( in combination )
a six-foot-deep trench
-
-
coming from or penetrating to a great depth
a deep breath
-
difficult to understand or penetrate; abstruse
-
learned or intellectually demanding
a deep discussion
-
of great intensity; extreme
deep happiness
deep trouble
-
absorbed or enveloped (by); engrossed or immersed (in)
deep in study
deep in debt
-
very cunning or crafty; devious
a deep plot
-
mysterious or obscure
a deep secret
-
(of a colour) having an intense or dark hue
-
low in pitch or tone
a deep voice
-
informal
-
to lose one's temper; react angrily
-
to act rashly
-
-
in a tricky position or in trouble
-
See end 1
noun
-
any deep place on land or under water, esp below 6000 metres (3000 fathoms)
-
-
a poetic term for the ocean
-
cricket the area of the field relatively far from the pitch
-
-
the most profound, intense, or central part
the deep of winter
-
a vast extent, as of space or time
-
nautical one of the intervals on a sounding lead, one fathom apart
adverb
-
far on in time; late
they worked deep into the night
-
profoundly or intensely
-
informal in reality, esp as opposed to appearance
she is a very kind person deep down
-
long ago
Other Word Forms
Derived Forms
Inflected Forms
Adjectives
Etymology
Origin of deep
First recorded before 900; Middle English dep, Old English dēop; akin to Gothic diups, Old Norse djupr, Dutch diep, Old High German tiof; akin to dip 1 ( def. ), dive ( def. )
Explanation
How deep a body of water is can be measured from the surface of water to the bottom. You should always be sure you know how deep a swimming pool is before demonstrating your backward somersault dive. Water can be deep or shallow, and exactly how deep it is can be measured. You can also describe a space not made of water as deep — like when you discover a little house made of candy deep, or far, in the woods. Things can even be figuratively deep when they are extreme, like "deep thoughts" or a "deep recession." The Old English word deop means "deep," but it also means, "awful, mysterious, and solemn."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The Camp David property - set deep in Catoctin Mountain Park in Frederick County, Maryland - was first taken over as a retreat by President Franklin Roosevelt, who nicknamed it "Shangri-La".
From BBC ● Oct. 8, 2026
Some already have offers for 2027 or are deep in the interview process.
From The Wall Street Journal ● Oct. 8, 2026
The formal dining room is to the right, while a moody sitting room with deep purple walls and coffered ceilings is to the left.
From MarketWatch ● Oct. 7, 2026
Researchers have long questioned whether violent behavior is rooted mainly in deep evolutionary history or is more strongly influenced by social and cultural forces.
From Science Daily ● Oct. 7, 2026
The cell was deep and narrow, scarcely wider than the door.
From "The Hiding Place" by Corrie ten Boom
On Thursday, the two leaders will formally ratify the 2025 Kensington Treaty, a partnership committing both countries to tackle hostile activity through deeper cooperation on science, technology, defence, security and growth.
From BBC ● Oct. 7, 2026
Coming newsletters will take deeper dives into some of the more intriguing ballot measures.
From The Wall Street Journal ● Oct. 7, 2026
Other evidence already hints that animals could have a much deeper evolutionary history than their body fossils indicate.
From Science Daily ● Oct. 7, 2026
Those from deeper in space carry clues about cosmic mysteries, like the supermassive black holes at the heart of galaxies.
From Barron's ● Oct. 6, 2026
Akira hopped off Dodger and walked deeper into the grove while her horse grazed.
From "Two Degrees" by Alan Gratz
Metallica has one of the deepest catalogs and intensely-attached fandoms in rock.
From Los Angeles Times ● Oct. 4, 2026
Every day Yvan Durig, owner and captain of the Lac des Brenets navigation company, measures the level of the remaining basin of water which is shrinking away at the very deepest bit of the lake.
From Barron's ● Oct. 4, 2026
"We would like to pass on our deepest sympathies to his family and friends and our thoughts are with them at this incredibly difficult time."
From BBC ● Sep. 30, 2026
If they could be produced at the LHC, their existence might help physicists address some of the deepest unanswered questions about spacetime and gravity.
From Science Daily ● Sep. 23, 2026
And in early 1985, Ames realized that he did possess something of great value: the CIA's deepest secrets.
From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
