tube

nouns

conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
is derived from
electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
a hollow cylindrical shape
(anatomy) any hollow cylindrical body structure
is derived from
an electric railway operating below the surface of the ground (usually in a city)
"in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"

verbs

provide with a tube or insert a tube into
is a type of (narrower)
give something useful or necessary to
"We provided the room with an electrical heater"
convey in a tube
"inside Paris, they used to tube mail"
is derived from
is a type of (narrower)
take something or somebody with oneself somewhere
"Bring me the box from the other room"; "Take these letters to the boss"; "This brings me to the main point"
ride or float on an inflated tube
"We tubed down the river on a hot summer day"
is a type of (narrower)
be carried or travel on or in a vehicle
"I ride to work in a bus"; "He rides the subway downtown every day"
place or enclose in a tube
is a type of (narrower)
enclose or enfold completely with or as if with a covering
"Fog enveloped the house"