#streambed__creek_bed__creekbed  a channel occupied (or formerly occupied) by a stream
  supertype:  bed.natural_depression__bottom  a depression forming the ground under a body of water; "he searched for treasure on the ocean bed"
  subtype:  dry_wash__drywash__wash  (western United States) the dry bed of an intermittent stream (as at the bottom of a canyon)

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