a long, hollow cylinder of metal, plastic, glass, etc., for holding or transporting something, chiefly liquids or gases.
A straw itself will not hold up well to this experiment, so see if you can get a tube of glass or plastic.
a thing in the form of or resembling a tube, in particular.
Three works could be manipulated; the massed tubes formed a square or circle mounted on a base that allowed a segment or the whole piece to be rotated by hand.
the subway system in London.
Today's hot topic was the Tube lines of the London Underground.
a sealed container, typically of glass and either evacuated or filled with gas, containing two electrodes between which an electric current can be made to flow.
Early diodes in electronics were made from metal plates sealed inside evacuated glass tubes , which could be seen glowing in the innards of old radio sets.