From Longman Dictionary of Contemporary Englishdredgerdredg‧er /ˈdredʒə $ -ər/ (also dredge) noun [countable] TTWa machine or ship used for digging or removing mud and sand from the bottom of a river, lake etc
Examples from the Corpus
dredger• Would it be possible, for example, to have a dredger clear all the silt, rubbish and vegetation?• A dredger was sunk due to the defendant's negligence.• The plaintiffs could not afford to buy a new dredger and had to hire one.• To move over long distances the dredger has to be towed by a tug.• The owners of the dredger required it to complete a contract which contained an onerous penalty clause.• The dredger represents a major technological advance for the miners. 