the tube that develops from the wall of a pollen grain and, in seed plants, provides a passage through which the male nuclei reach the embryo sac to effect fertilization

(anatomy) In humans and other land vertebrates, a tube that links the nasopharynx to the cavity of the middle ear to allow the equalization of the pressure on both sides of the eardrum.

a photoelectric device for intensifying faint astronomical images

A device in some early internal combustion engines that ignited the fuel/air mixture in a tube heated by a flame

An inflatable rubber tube inserted into the casing of a pneumatic tyre/tire.

A phototube in which an electric current flows when a certain illumination is reached; used as a relay

(electronics) A type of electron tube that controls electron current through vacuum between electrodes within a sealed container, usually of glass or metal and often designed to be easily installed in and removed from the equipment in which it is used.

Alternative letter-case form of Fallopian tube

(physics) Any of several electronic devices that control electron current through vacuum, gas or vapor between electrodes within a sealed container, usually of glass or metal and often designed to be easily installed in and removed from the equipment in which it is used.

(aviation) A pressure measuring instrument used to measure fluid flow velocity, especially used to determine the airspeed of an aircraft.