verb-intransitive. To take fish, or other marine animals, with a trawl.n. A fishing line, often extending a mile or more, having many short lines bearing hooks attached to it. It is used for catching cod, halibut, etc.; a boulter.n. A large bag net attached to a beam with iron frames at its ends, and dragged at the bottom of the sea, -- used in fishing, and in gathering forms of marine life from the sea bottom.