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.
the quality of being deep; deepness.
complexity or obscurity, as of a subject: a question of great depth.
gravity; seriousness.
emotional profundity: the depth of someone's feelings.
intensity, as of silence, color, etc.
lowness of tonal pitch: the depth of a voice.
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.
a high degree of such knowledge, insight, etc.
Often depths.a deep part or place: from the depths of the ocean.
an unfathomable space; abyss: the depth of time.
Sometimes depths.the farthest, innermost, or extreme part or state: the depth of space; the depths of the forest; the depths of despair.
Usually depths.a low intellectual or moral condition: How could he sink to such depths?
the part of greatest intensity, as of night or winter.
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
in depth, extensively or thoroughly: Make a survey in depth of the conditions.
out of/beyond one's depth,
in water deeper than one's height or too deep for one's safety.
beyond one's knowledge or capability: The child is being taught subjects that are beyond his depth.
Origin of depth
1350–1400;Middle Englishdepthe, equivalent to dep (Old Englishdēopdeep) + -the-th1
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.
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.
