A trawlnet is a large fishing net that is typically dragged behind a boat to catch fish or other aquatic creatures. There are several synonyms for the word trawlnet, including dragnet, seine, and gill net. A dragnet is a large net that is used to catch fish or other creatures by dragging it along the bottom of a body of water. A seine is a type of fishing net that is used to encircle a school of fish and then hauled in. A gill net is a type of fishing net that is constructed of fine mesh and is hung vertically in the water. It captures fish by entangling them in its mesh as they swim by.