| pipe(noun, thing, course, opening, drain) |
| subway(noun, line, thing, track, hole) |
| hose(noun, thing, cylinder, conduit, pipe) |
| conduit(noun, line, thing, way, drain) |
| channel(noun, line, water, way, course) |
| underground |
| metro(noun, line, track, underground, railway) |
| line(noun, thing, way, track, trail) |
| duct(noun, line, way, course, drain) |
| shaft(noun, thing, opening, hole, channel) |
| cylinder(noun, container, holder, reel, pipe) |
| television(noun, visual, electricity) |
| tunnel(noun, opening, conduit, passageway, hose) |
| vacuum tube(noun, expression, idiom) |
| tubing |
| canal(noun, line, way, opening, drain) |
| funnel(opening, conduit, airpipe) |
| pipeline(noun, channel, passage, cylinder, pipe) |
| piping |
| roll(noun, wave, breaker, whitecap) |