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."

Definitions of deep
  1. adjective
    having great spatial extension or penetration downward or inward from an outer surface or backward or laterally or outward from a center; sometimes used in combination
    “a deep well”
    “a deep dive”
    deep water”
    “a deep casserole”
    “a deep gash”
    deep massage”
    deep pressure receptors in muscles”
    deep shelves”
    “a deep closet”
    “surrounded by a deep yard”
    “hit the ball to deep center field”
    “in deep space”
    “waist- deep
    abysmal, abyssal, unfathomable
    resembling an abyss in depth; so deep as to be unmeasurable
    extremely deep
    of or carried on in waters of great depth
    profound, unfathomed, unplumbed, unsounded
    situated at or extending to great depth; too deep to have been sounded or plumbed
    (of e.g. closets or refrigerators) extending very far enough back to allow a person to enter
    of depth; not capable of being sounded or measured
    see moresee less
    lacking physical depth; having little spatial extension downward or inward from an outer surface or backward or outward from a center
    ankle-deep, knee-deep
    coming only to the ankle or knee
    shallow enough to be crossed by walking or riding on an animal or in a vehicle
    relating to the region of shallow water adjoining the seacoast
    reefy, shelfy, shelvy, shoaly
    full of submerged reefs or sandbanks or shoals
    show more antonyms...
  2. adjective
    relatively thick from top to bottom
    deep carpets”
    deep snow”
    not thin; of a specific thickness or of relatively great extent from one surface to the opposite usually in the smallest of the three solid dimensions
  3. adjective
    extending relatively far inward
    “a deep border”
    broad, wide
    having great (or a certain) extent from one side to the other
  4. adjective
    very distant in time or space
    deep in the past”
    deep in enemy territory”
    deep in the woods”
    “a deep space probe”
    separated in space or coming from or going to a distance
  5. noun
    literary term for an ocean
    “denizens of the deep
    see moresee less
    type of:
    a large body of water constituting a principal part of the hydrosphere
  6. noun
    a long steep-sided depression in the ocean floor
    synonyms: oceanic abyss, trench
    see moresee less
    show 4 examples...
    hide 4 examples...
    Atacama Trench
    a depression in the floor of the Pacific Ocean off the coast of Chile
    Bougainville Trench
    a depression in the floor of the Pacific Ocean between New Guinea and the Solomon Islands
    Japan Trench
    a depression in the floor of the Pacific Ocean to the northeast of Japan that reaches depths of 30,000 feet
    Nares Deep
    a depression in the floor of the Atlantic Ocean to the north of Haiti and Puerto Rico
    type of:
    depression, natural depression
    a sunken or depressed geological formation
  7. adverb
    to a great distance
    “penetrated deep into enemy territory”
    “went deep into the woods”
  8. adverb
    to an advanced time
    deep into the night”
    synonyms: late
  9. adverb
    to a great depth;far down
    “dug deep
    synonyms: deeply
  10. adjective
    “in deep trouble”
    deep happiness”
    possessing or displaying a distinctive feature to a heightened degree
  11. adjective
    large in quantity or size
    deep cuts in the budget”
    big, large
    above average in size or number or quantity or magnitude or extent
  12. adjective
    strong; intense
    deep purple”
    synonyms: rich
    colorful, colourful
    having striking color
  13. adjective
    relatively deep or strong; affecting one deeply
    “a deep breath”
    “a deep sigh”
    deep concentration”
    deep emotion”
    “a deep trance”
    “in a deep sleep”
    heavy, profound, sound, wakeless
    (of sleep) deep and complete
    coming from deep within one
    see moresee less
    not deep or strong; not affecting one deeply
    light, wakeful
    (of sleep) easily disturbed
    show more antonyms...
  14. adjective
    (of darkness) very intense
    “a face in deep shadow”
    deep night”
    synonyms: thick
    possessing or displaying a distinctive feature to a heightened degree
  15. adjective
    marked by depth of thinking
    deep thoughts”
    “a deep allegory”
    showing intellectual penetration or emotional depth
  16. noun
    the central and most intense or profound part
    “in the deep of night”
    “in the deep of winter”
    see moresee less
    type of:
    time between the beginning and the end of a temporal period
  17. adjective
    of an obscure nature
    “a deep dark secret”
    synonyms: cryptic, cryptical, inscrutable, mysterious, mystifying
    incomprehensible, inexplicable
    incapable of being explained or accounted for
  18. adjective
    difficult to penetrate; incomprehensible to one of ordinary understanding or knowledge
    “a deep metaphysical theory”
    synonyms: abstruse, recondite
    confined to and understandable by only an enlightened inner circle
  19. adjective
    exhibiting great cunning usually with secrecy
    deep political machinations”
    “a deep plot”
    marked by skill in achieving a desired end especially with cunning or craft
  20. adjective
    having or denoting a low vocal or instrumental range
    “a deep voice”
    synonyms: bass
    low, low-pitched
    used of sounds and voices; low in pitch or frequency
  21. adjective
    with head or back bent low
    “a deep bow”
    literal meanings; being at or having a relatively small elevation or upward extension
Word Family

Look up deep for the last time

Close your vocabulary gaps with personalized learning that focuses on teaching the words you need to know.

VocabTrainer -'s Vocabulary Trainer