depth

[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.
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
16.
in depth, extensively or thoroughly:
Make a survey in depth of the conditions.
17.
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.
Origin
1350-1400; Middle English depthe, equivalent to dep (Old English dēop deep) + -the -th1
Related forms
depthless, adjective
Antonyms
2. shallowness. 9. superficiality.
British Dictionary definitions for out of one's depth

depth

/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 pl) a deep, far, inner, or remote part, such as an inaccessible region of a country
10.
(often pl) the deepest, most intense, or most severe part: the depths of winter
11.
(usually pl) a low moral state; demoralization: how could you sink to such depths?
12.
(often pl) a vast space or abyss
13.
beyond one's depth, out of one's depth
  1. in water deeper than one is tall
  2. beyond the range of one's competence or understanding
14.
in depth, thoroughly or comprehensively See also in-depth
Word Origin
C14: from depdeep + -th1
Word Origin and History for out of one's depth

depth

n.

late 14c., apparently formed in Middle English on model of length, breadth; from Old English deop "deep" (see deep) + -th (2). Replaced older deopnes "deepness." Though the English word is relatively recent, the formation is in Proto-Germanic, *deupitho-, and corresponds to Old Saxon diupitha, Dutch diepte, Old Norse dypð, Gothic diupiþa.

out of one's depth in Medicine

depth (děpth)
n.
The extent, measurement, or dimension downward, backward, or inward.

Idioms and Phrases with out of one's depth

out of one's depth

Also, beyond one's depth. Outside one's understanding or competence, as in He was out of his depth in that advanced calculus class, or The conductor realized that playing the fugue at the right tempo was beyond their depth. This expression alludes to being in water so deep that one might sink. [ c. 1600 ]
Also see: over one's head

depth

see: