tube

n. hollow cylinder; elongated hollow object; pipette, pipe; tunnel; subway, metro (British)

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Noun
1. conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
(synonym) tubing
(hypernym) conduit
(hyponym) barrel, gun barrel
2. electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
(synonym) vacuum tube, thermionic vacuum tube, thermionic tube, electron tube, thermionic valve
(hypernym) electronic device
(hyponym) acorn tube
(part-holonym) circuit, electrical circuit, electric circuit
(part-meronym) anode
3. a hollow cylindrical shape
(synonym) pipe
(hypernym) cylinder
4. (anatomy) any hollow cylindrical body structure
(synonym) tube-shaped structure
(hypernym) structure, anatomical structure, complex body part, bodily structure, body structure
(hyponym) tubule
(classification) anatomy, general anatomy
5. electric underground railway
(synonym) metro, subway, underground
(hypernym) railway, railroad, railroad line, railway line, railway system

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Verb
1. provide with a tube or insert a tube into
(hypernym) supply, provide, render, furnish
(derivation) tube-shaped structure
2. convey in a tube; "inside Paris, they used to tube mail"
(hypernym) bring, convey, take
(derivation) tube-shaped structure
3. ride or float on an inflated tube; "We tubed down the river on a hot summer day"
(hypernym) ride
4. place or enclose in a tube
(hypernym) envelop, enfold, enwrap, wrap, enclose
(derivation) tube-shaped structure

nf. tube, elongated hollow object

nm. tube, pipe; tunnel, conduit