Definition of dredge in English Turkish dictionary one who dredges boat which dredges dredging machine dredger a barge or barge-like vessel used for dredging dredger A box with holes in its lid used for sprinkling flour, as on meat or a breadboard called also dredging box, drudger, and drudging box dredger A dredger is a boat which is fitted with a special machine that is used to increase the size of harbours, rivers, and canals. dredge Synonyms: drag Search (as the bottom of a body of water) for something valuable or lost.