deep
Americanadjective
-
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:
No one has tried operating a commercial nuclear reactor deep underground—until now.
From The Wall Street Journal ● Jul. 28, 2026
They added logs and woody debris to the water to create deep pools and other places for baby fish to hide.
From Los Angeles Times ● Jul. 28, 2026
"Looking back I feel a deep sense of guilt and shame for not recognising the warning signs," he said.
From BBC ● Jul. 28, 2026
“We are in very deep talks with Iran,” Trump said.
From MarketWatch ● Jul. 28, 2026
“Try harder. You can do this, La. Now take nice, slow deep breaths,” she instructs.
From "Split the Sky" by Marie Arnold
Sometimes the lyrics on “Reality Awaits” are funny and self-aware, sometimes they hint at Mr. Casablancas’s deeper concerns, and sometimes they’re cryptic and arch.
From The Wall Street Journal ● Jul. 28, 2026
The warming of the ocean surface is forcing anchovies and sardines -- which the mammals eat -- to seek cooler waters, either at deeper levels or farther north.
From Barron's ● Jul. 27, 2026
At the same time, those efforts should not be presented as replacements for deeper changes within organizations.
From Science Daily ● Jul. 25, 2026
Both players would be capable of taking turns in dropping deeper to maintain the balance of the team if strong carriers of the ball like Marc Guehi or Josko Gvardiol were to push forward.
From BBC ● Jul. 25, 2026
Through the streets and suburbs of Haarlem, I bumped on my bicycle rims, bringing the message that joy runs deeper than despair.
From "The Hiding Place" by Corrie ten Boom
What true frontier AI can do—the deepest reasoning, the longest context and the most complex work—nothing in open source can match.
From The Wall Street Journal ● Jul. 27, 2026
He said he was "sorry" and offered his "deepest condolences".
From BBC ● Jul. 24, 2026
The oldest and deepest pollen and spores in the cores remained lightly colored.
From Science Daily ● Jul. 22, 2026
Mexico had just lost 3-2 to England, extinguishing the hope that it could parlay its World Cup co-host role into the deepest tournament run in the country’s history.
From Los Angeles Times ● Jul. 12, 2026
We only got letters from one person, and the envelopes were always the brightest, deepest, and most entirely pink thing ever created.
From "Hope Springs" by Jaime Berry
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.
