Depth

noun

1. The vertical distance below a surface; the degree to which something is deep

   "Measure the depth of the water in this part of the bay."

2. The distance between the front and the back, as the depth of a drawer or closet
3. The intensity, complexity, strength, seriousness or importance of an emotion, situation, etc.

   "The depth of her misery was apparent to everyone."

4. Lowness

   "the depth of a sound"

5. (colors) the total palette of available colors