1. (n.) A hollow cylinder, of any material, used for the conveyance of fluids, and for various other purposes; a pipe.

2. (n.) A telescope.

3. (n.) A vessel in animal bodies or plants, which conveys a fluid or other substance.

4. (n.) The narrow, hollow part of a gamopetalous corolla.

5. (n.) A priming tube, or friction primer. See under Priming, and Friction.

6. (n.) A small pipe forming part of the boiler, containing water and surrounded by flame or hot gases, or else surrounded by water and forming a flue for the gases to pass through.

7. (n.) A more or less cylindrical, and often spiral, case secreted or constructed by many annelids, crustaceans, insects, and other animals, for protection or concealment.

8. (n.) One of the siphons of a bivalve mollusk.

9. (v. t.) To furnish with a tube; as, to tube a well.

Amtrak L Photronic cell adjutage amplifier anode attenuator audio-frequency tube baggage train ballast regulator ballast tube barrel base beam-switching tube bole branch cable railroad cable railway cask catheter cathode cathode-ray tube channel choo-choo cog railroad cog railway color kinescope column convertor current regulator cylinder cylindroid damper detector direct-viewing tube discharge tube discriminator dissector tube doubler drainpipe drum efflux tube el electric electric railway electric train electrode electron-image tube elevated elevated railway embankment express express train feeder feeder line filament fire hose flier flue pipe flume focus tube freight freight train freighter funicular funnel garden hose gas phototube gas pipe generator goods train gravity-operated railway grid horse railway hose hosepipe iconoscope image dissector image iconoscope interurban inverter junction kinescope light railroad lightning express limited limiter line local local-oscillator tube main line metro milk train mixer tube modulator monorail monoscope multiplier multiplier phototube multipurpose tube multivibrator nipple organ pipe oscillator output tube parliamentary parliamentary train passenger train phase inverter photocathode photoconductor cell photomultiplier tube phototube photovoltaic cell picture tube pillar pipe pipeline pipette piping plate power tube pulse generator put through channels rack railway rack-and-pinion railroad rack-and-pinion railway radio tube radio-frequency tube rail rail line railroad railroad train railway rattler receiving tube rectifier tube reed reed pipe regulator repeater roadbed roadway roll roller rolling stock rouleau shuttle shuttle train siamese siamese connection sidetrack siding siphon snorkel soft phototube soil pipe special standpipe steam pipe stem straw streamliner street railway streetcar line subway switchback tap terminal terminus track train tram tramline transducer trestle trigatron trigger tube trolley line trunk trunk line tubing tubulation tubule tubulet tubulure turnout underground vacuum phototube vacuum tube valve waste pipe water pipe way train