1. The condition or quality of being deep.
2. 1. The extent, measurement, or dimension downward, backward, or inward: dove to a depth of 30 feet; shelves with enough depth to store the large boxes.
   2. The measurement or sense of distance from an observation point, such as linear perspective in painting.
3. A deep part or place. Often used in the plural: the ocean depths; in the depths of the forest.
4. 1. The most profound or intense part or stage: the depth of despair; an experience that touched the depths of tragedy.
   2. Intensity; force: had not realized the depth of their feelings for one another.
5. The severest or worst part: in the depth of an economic depression.
6. A low point, level, or degree: Production has fallen to new depths.
7. Intellectual complexity or penetration; profundity: a novel of great depth.
8. The range of one's understanding or competence: I am out of my depth when it comes to cooking.
9. Strength held in reserve, especially a supply of skilled or capable replacements: a team with depth at every position.
10. The degree of richness or intensity: depth of color.
11. Lowness in pitch.
12. Complete detail; thoroughness: the depth of her research; an interview conducted in great depth.

[Middle English depthe, from dep, deep. See deep.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.