Merriam-Webster Collegiate Dictionary - sewer

 I. noun  Etymology: Middle English, from Anglo-French asseour, literally, seater, from Anglo-French asseer to seat — more at assize  Date: 14th century a medieval household officer often of high rank in charge of serving the dishes at table and sometimes of seating and tasting  II. noun  Date: 14th century one that sews  III. noun  Etymology: Middle English, from Anglo-French, from as~, essiver to drain, from Vulgar Latin *exaquare, from Latin ex- + aqua water — more at island  Date: 15th century an artificial usually subterranean conduit to carry off sewage and sometimes surface water (as from rainfall)