depression

1. A hollow of any size on a plain surface having no natural outlet for surface drainage. 2. A structurally low area in the crust of the earth. 3. An area of low pressure; usually applied to a certain stage in the development of a tropical cyclone, to migratory lows and troughs, and to upper-level lows and troughs that are only weakly developed. Also known as low.

Related terms:

• V-shaped depression
• wave depression
• depression storage
• depression spring
• wet-bulb depression
• upper-level cyclone
• scour depression
• ring depression
• peripheral depression
• Cone of Depression