dredging

noun

1. a device consisting of a net attached to a frame, dragged along the bottom of a river, bay, etc. to gather shellfish, marine plant specimens, etc.
2. an apparatus for scooping or sucking up mud, sand, rocks, etc., as in deepening or clearing channels, harbors, etc.
3. a barge or other boat equipped with a dredge

Origin: prob. < MDu dregge, akin to drag

transitive verb dredged, dredging

1. to search for or gather (up) with or as with a dredge
2. to enlarge or clean out (a river channel, harbor, etc.) with a dredge

intransitive verb

1. to use a dredge
2. to search as with a dredge