sewer (n.) Look up sewer at Dictionary.com
"conduit," c.1400, from Anglo-French sewere, Old North French sewiere "sluice from a pond" (13c.), literally "something that makes water flow," from shortened form of Gallo-Romance *exaquaria (cf. Middle French esseveur), from Latin ex- "out" + aquaria, fem. of aquarius "pertaining to water," from aqua "water."