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:
StepFun's chairman Yin Qi said "deep partnerships" had been established with several major Chinese platforms, including Alipay and ride-hailing giant Didi, according to a sponsored article in state news agency Xinhua.
From Barron's ● Jul. 19, 2026
At the time, Xiao’s unit was also developing deep ties with China.
From The Wall Street Journal ● Jul. 19, 2026
Captain Harry Kane ended up so deep because "that's what you do if you defend in a block".
From BBC ● Jul. 18, 2026
But perhaps CXMT, bolstered by the deep pockets of Hefei’s municipal-investment arm, would be able to accomplish what GigaDevice couldn’t.
From MarketWatch ● Jul. 18, 2026
For in some deep part of me I knew already that there would not—soon or ever—be anyone else.
From "The Hiding Place" by Corrie ten Boom
He seemed to savor the chance to go deeper, to look more closely at our innate capacity for acts both moral and depraved.
From Salon ● Jul. 17, 2026
Before attempting to reshape an entire planet, we first need a much deeper understanding of Mars itself, along with the scientific, environmental, and ethical consequences of altering it.
From Science Daily ● Jul. 17, 2026
A fifth of us are guilty of regularly procrastinating but the type of procastinator we are can reveal something deeper about us, say researchers.
From BBC ● Jul. 17, 2026
He said they see “potential for a deeper decline because you’re going to be cycling through some high-growth, high-inflation numbers from the first half of this year.”
From MarketWatch ● Jul. 17, 2026
“We had boots on, but after deeper pockets of hot ash we climbed on logs to cool our feet.”
From "Mountain of Fire" by Rebecca E. F. Barone
"We extend our deepest condolences to his family, loved ones, and everyone now grieving this unimaginable loss."
From BBC ● Jul. 14, 2026
It has witnessed some of our greatest triumphs and deepest failures.
From Salon ● Jul. 10, 2026
The cuts include the deepest overhaul in Xbox's history, with approximately 3,200 gaming jobs to be shed over the coming fiscal year, including positions at four studios that are being spun off or sold.
From Barron's ● Jul. 6, 2026
Guinness World Records recognized the expedition as the deepest scientific ocean drilling project ever completed.
From Science Daily ● Jul. 5, 2026
Now he confronted the most challenging, the deepest, part of the stream.
From "Abel's Island" by William Steig
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.