tuben.[L. tubus; akin to tuba a trumpet: cf F. tube.]1. A hollow cylinder, of any material, used for the conveyance of fluids, and for various other purposes; a pipe.()2. A telescope.(Milton.)3. A vessel in animal bodies or plants, which conveys a fluid or other substance.()4. (Bot.) The narrow, hollow part of a gamopetalous corolla.()5. (Gun.) A priming tube, or friction primer. See under Priming, and Friction.()6. (Steam Boilers) 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. (Zol.) A more or less cylindrical, and often spiral, case secreted or constructed by many annelids, crustaceans, insects, and other animals, for protection or concealment. See Illust. of Tubeworm.()8. (Elec. Railways) A tunnel for a tube railway; also (Colloq.), a tube railway; a subway.()Capillary tube, a tube of very fine bore. See Capillary. -- Fire tube (Steam Boilers), a tube which forms a flue. -- Tube coral. (Zol.) Same as Tubipore. -- Tube foot (Zol.), one of the ambulacral suckers of an echinoderm. -- Tube plate, or Tube sheet (Steam Boilers), a flue plate. See under Flue. -- Tube pouch (Mil.), a pouch containing priming tubes. -- Tube spinner (Zol.), any one of various species of spiders that construct tubelike webs. They belong to Tegenaria, Agelena, and allied genera. -- Water tube (Steam Boilers), a tube containing water and surrounded by flame or hot gases.()v. t. To furnish with a tube; as, to tube a well.()