Meaning of “tube” - Learner’s Dictionary

tube

noun uk us /tjuːb/
PIPE [ C ]

B2 a pipe made of glass, plastic, metal, etc, especially for liquids or gases to flow through

CONTAINER [ C ]

B1 a long, thin container for a soft substance, that you press to get the substance out:

a tube of toothpaste
the Tube

B1 the system of railways under the ground in London:

I got the Tube to Oxford Circus.
→ See also test tube

(Definition of “tube” from the Cambridge Learner’s Dictionary © Cambridge University Press)