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
c(1)
: tunnel
d
: the basically cylindrical section between the mouthpiece and bell that is the fundamental part of a wind instrument
2a
: 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
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
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Merriam-Webster unabridged
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Time Traveler for tube
The first known use of tube was in 1651
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