1. the distance from the top or surface to the bottom of something
2. the distance from the front to the back of something
3. the quality of being intense, complete, or thorough

Examples

• The pool has a depth of eight feet.
• Measure the depth of the bookshelf before buying it.
• She studied the subject in great depth.
• His poetry shows remarkable depth of emotion.
• The ship sank into the depths of the ocean.
• The depth of her knowledge impressed everyone.
• We need to dig to a depth of three feet.