THESAURUS
Culvert
aqueduct, arroyo, bed, canal, creek bed, donga, dry bed, flume, gulch, gully, gullyhole, headrace, irrigation ditch, nullah, race, river bed, riverway, runnel, sluice, spillbox, spillway, stream bed, streamway, swash, swash channel, tailrace, wadi, water carrier, water channel, water furrow, water gap, water gate, watercourse, waterway, waterworks
ROGET THESAURUS
Culvert
Conduit
N
conduit, channel, duct, watercourse, race, head race, tail race, abito, aboideau, aboiteau, bito, acequia, acequiador, acequiamadre, arroyo, adit, aqueduct, canal, trough, gutter, pantile, flume, ingate, runner, lock-weir, tedge, vena, dike, main, gully, moat, ditch, drain, sewer, culvert, cloaca, sough, kennel, siphon, piscina, pipe, funnel, tunnel, water pipe, waste pipe, emunctory, gully hole, artery, aorta, pore, spout, scupper, adjutage, ajutage, hose, gargoyle, gurgoyle, penstock, weir, flood gate, water gate, sluice, lock, valve, rose, waterworks, pipeline, vascular.