(informal in Portugal, literary, archaic or regional in Brazil) you; thou (singular second person pronoun) / (Brazil, colloquial, proscribed) second-person singular prepositional pronoun;

(onomatopoeia) the sound produced by a telephone after one of the callers hangs up

(music) tuba (a large brass musical instrument)

tubular (shaped like a tube)

tube / pipe / tube

(Portugal) tailpipe; exhaust pipe

(anatomy) Fallopian tube (duct in female mammals through which ova pass from the ovaries to the uterus)

(anatomy) Eustachian tube (tube that links the pharynx to the cavity of the middle ear)

(electronics) cathode ray tube (CRT)