A single-ended thimble tube in a boiler, with an internal tube to encourage circulation.

A tapered thermic syphon water-tube inserted in the furnace of a Lancashire boiler.

A tube for the removal of mud and rock debris out to the surface of a caisson.

A kind of phytoclast consisting of micrometre-scale tubes with a banded internal ornamentation, known from terrestrial/freshwater settings from the early Silurian onwards.

(electronics, becoming dated) In a television set, before the development of LED screens, the cathode ray tube which produced moving images on its surface.

(electronics) A type of vacuum tube that detects electromagnetic radiation in the range from ultraviolet to infrared, including the visible spectrum, and them amplifies the detection induced current into an output signal

plural of tube well

(video games, slang) A very overpowered firearm, especially a grenade launcher.

Synonym of steerer tube

(cycling) The part of the fork that is inserted into the head tube of the frame, and is used to attach the fork to the frame using a headset.