Meaning of alluvial fan

allu'vial fan'

Pronunciation: [key]
— Physical Geog. Physical Geog.
  1. a fan-shaped alluvial deposit formed by a stream where its velocity is abruptly decreased, as at the mouth of a ravine or at the foot of a mountain. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.