Definitions:

1. A naturally formed, lower-elevation area of land, often bowl-shaped or basin-like, that may collect water, support wetlands, or form part of a drainage system. NOUN
   • A natural depression in the desert became an oasis after heavy rains.
2. Refers to a low-lying area or sunken landform that occurs naturally in the Earth's surface, often caused by geological or climatic processes such as erosion, subsidence, or glacial activity. NOUN
   • The lake sits on a natural depression formed by ancient glacial movement.

Synonyms:

• basin
• depression
• subsidence
• swale
• trench