depth

American  

[depth] / dɛpθ /

noun

1. a dimension taken through an object or body of material, usually downward from an upper surface, horizontally inward from an outer surface, or from top to bottom of something regarded as one of several layers.

2. the quality of being deep; deepness.

3. complexity or obscurity, as of a subject.

   a question of great depth.

4. gravity; seriousness.

   I don't think you recognize the depth of the problem.

   Synonyms:

   weight, significance, importance, import

5. emotional profundity.

   the depth of someone's feelings.

6. intensity, as of silence, color, etc.

7. lowness of tonal pitch.

   the depth of a voice.

8. the amount of knowledge, intelligence, wisdom, insight, feeling, etc., present in a person's mind or evident either in some product of the mind, as a learned paper, argument, work of art, etc., or in the person's behavior.

9. a high degree of such knowledge, insight, etc.

10. Often depths a deep part or place.

    from the depths of the ocean.

11. an unfathomable space; abyss.

    the depth of time.

12. Sometimes depths the farthest, innermost, or extreme part or state.

    the depth of space;

    the depths of the forest;

    the depths of despair.

13. Usually depths. a low intellectual or moral condition.

    How could he sink to such depths?

14. the part of greatest intensity, as of night or winter.

15. Sports. the strength of a team in terms of the number and quality of its substitute players.

    With no depth in the infield, an injury to any of the regulars would be costly.

---

idioms

1. in depth, extensively or thoroughly.

   Make a survey in depth of the conditions.

2. out of / beyond one's depth,

   1. in water deeper than one's height or too deep for one's safety.

   2. beyond one's knowledge or capability.

      The child is being taught subjects that are beyond his depth.

depth British  

/ dɛpθ /

noun

1. the extent, measurement, or distance downwards, backwards, or inwards

2. the quality of being deep; deepness

3. intensity or profundity of emotion or feeling

4. profundity of moral character; penetration; sagacity; integrity

5. complexity or abstruseness, as of thought or objects of thought

6. intensity, as of silence, colour, etc

7. lowness of pitch

8. nautical the distance from the top of a ship's keel to the top of a particular deck

9. (often plural) a deep, far, inner, or remote part, such as an inaccessible region of a country

10. (often plural) the deepest, most intense, or most severe part

    the depths of winter

11. (usually plural) a low moral state; demoralization

    how could you sink to such depths?

12. (often plural) a vast space or abyss

13. 1. in water deeper than one is tall

    2. beyond the range of one's competence or understanding

14. thoroughly or comprehensively See also in-depth

---

depth More Idioms  

1. see in depth; out of one's depth.

---

Other Word Forms

• depthless
  adjective

Etymology

Origin of depth

First recorded in 1350–1400; Middle English depthe, equivalent to deep + -th ¹

Explanation

Depth is the measure of how deep something goes. The swimming pool has a depth of six feet. The well has an unknown depth. People can be deep as well—you know by looking at some people that they have depth. Depth goes with other measure words that end in "th." Length is how long something is. Breadth is how wide or broad. The expression "plumb the depths" means to take a measure of how deep something goes. Depth also can mean deepness—your English teacher might instruct you to write papers with depth.

Example Sentences

"This kind of information is critical for marine park planning and management, because it gives us a much clearer picture of what species are present and how communities are structured across depth."

From Science Daily • May 14, 2026

As a result, when a domestic shock hits, the system lacks the diversified global networks and capital depth needed to absorb the blow.

From The Wall Street Journal • May 12, 2026

The dish — essentially Italian rice and peas — sits somewhere between risotto and stew, using both puréed and whole peas for texture and depth.

From Salon • May 12, 2026

Nick: "Rohl has to go. Being better than the worst manager Rangers have ever had is not reason enough to stick with someone who is clearly out of his depth."

From BBC • May 11, 2026

The sounds of voices, small and whispery, still floated from the depth of the woods.

From "The Birchbark House" by Louise Erdrich

Related Words

• acumen
• intellect
• intelligence
• sense