a shallow depression left after the wind has eroded a layer of exposed soil

Deflation, in geology, erosion by wind of loose material from flat areas of dry, uncemented sediments such as those occurring in deserts, dry lake beds, floodplains, and glacial outwash plains. Clay and silt-sized particles are picked up by turbulent eddies in wind and may be carried for hundreds of kilometres; they later settle to form loess deposits. Local areas subjected to deflation may result in deflation hollows or blowouts. These may range from 3 m (10 feet) in diameter and less than a metre deep to several kilometres in diameter and several hundred metres in depth.

A surface depression or hollow commonly found in arid and semiarid regions caused by wind erosion. Also see the related blowout depression.