Definition of tube
1
:any of various usually cylindrical structures or devices: such as
a
:a hollow elongated cylinder;
especially
:one to convey fluids
b
:a soft tubular container whose contents (such as toothpaste) can be removed by squeezing
d
:the basically cylindrical section between the mouthpiece and bell that is the fundamental part of a wind instrument
2 a
:a slender channel (such as a fallopian tube or a pollen tube) within a plant or animal body :duct
b
:the narrow basal portion of a corolla with united petals or a calyx with united sepals
3
:inner tube
4 a
:electron tube;
especially
:vacuum tube
b
:cathode-ray tube;
especially
:a television picture tube
c
:television
5
:an article of clothing shaped like a tube
- a tube top
- tube socks
—
down the tube
or
down the tubes
:into a state of collapse or deterioration
