ETYM French seine, or as. segene, both from Latin sagena, Greek.
(Homonym: sane).
A large fishnet that hangs vertically, with floats at the top and weights at the bottom.

A French river that flows through the heart of Paris and then northward into the English Channel; Also called: Seine River.
French river rising on the Langres plateau NW of Dijon, and flowing 774 km/472 mi NW to join the English Channel near Le Havre, passing through Paris and Rouen.

To fish with a seine; catch fish with a seine.