depth

noun

ˈdepth 

plural depths ˈdepths  ˈdep(t)s 

1

a(1)

: a deep place in a body of water

fish living at great depths

(2)

: a part that is far from the outside or surface

the depths of the woods

(3)

: abyss sense 1

b(1)

: a profound or intense state (as of thought or feeling)

the depths of sorrow

also : a reprehensibly low condition

hadn't realized that standards had fallen to such depths

(2)

: the middle of a time (such as a season)

the depths of winter

(3)

: the worst part

the depths of the depression

2

mathematics

a

: the perpendicular (see perpendicular entry 1 sense 1b) measurement downward from a surface

the depth of a swimming pool

b

: the direct linear measurement from front to back

the depth of a bookshelf

3

: the quality of being deep

the depth of the pass

4

: the degree of intensity

depth of a color

also : the quality of being profound (as in insight) or full (as of knowledge)

the depth of her experience

5

: the quality or state of being complete or thorough

—used in the phrase in depth

a study will be made in depth

a subject being discussed in depth [=thoroughly, comprehensively]

compare in-depth

6

US, sports : the quality of having many good players

a team that lacks depth in the outfield

depthless

ˈdepth-ləs 

adjective

Phrases

beyond one's depth or out of one's depth

: beyond the limits of one's capabilities

an actor who is out of his depth in serious drama

Synonyms

• deepness
• drop

Examples of depth in a Sentence

These fish typically live at depths of 500 feet or more.

Students will test the temperature of the water at different depths.

The boat sank to a depth of several hundred feet.

measuring the depth of the water

the depth of a hole

The pool has a depth of 12 feet.

I began working at the factory during the depth of the Depression.

Recent Examples on the Web

With this technology, AI can improve liveness detection by assessing micro-movements, texture and 3D depth to distinguish actual users from photographs or masks. —Rohan Pinto, Forbes.com, 17 June 2025

Just because tweens spend more time online doesn’t mean their friendships lack depth. —Dia Gallo, Parents, 17 June 2025

The strawberry vanilla syrup adds depth, while the Simply Lemonade keeps it fresh and light. —Essence, 17 June 2025

The Mets surprised baseball with their depth this season, but if that depth isn’t performing, Senga’s loss will be much more difficult to absorb. —Abbey Mastracco, New York Daily News, 16 June 2025

Word History

Etymology

Middle English, from dep deep

First Known Use

14th century, in the meaning defined at sense 1a(1)

Phrases Containing depth

• depth charge
• depth of field
• depth perception
• depth psychology
• in-depth
• the depth of winter

Kids Definition

depth

noun

ˈdepth 

1

a

: something that is deep : a deep place or part (as of a body of water)

b

: a part that is far from the outside or surface

the depths of the woods

c

: abyss

2

a

: the middle of a time

the depth of winter

b

: an extreme state (as of despair)

3

: distance from top to bottom or from front to back

4

: the quality of being deep

depth of understanding

5

: degree of intensity

the depth of a color

depthless

-ləs 

adjective

Medical Definition

depth

noun

ˈdepth 

plural depths ˈdepth  ˈdep(t)s 

1

: the distance between upper and lower or between dorsal and ventral points of a body

2

: the quality of a state of consciousness, a bodily state, or a physiological function of being intense or complete

the depth of anesthesia

the depth of respiration