tube

noun

ˈtüb 

ˈtyüb

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

(2)

British : subway sense b

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

tubed

ˈtübd 

ˈtyübd

adjective

tubelike

ˈtüb-ˌlīk 

ˈtyüb-

adjective

see also:

down the tube

Synonyms of tube

• pipe
• conduit
• channel
• funnel

Examples of tube in a Sentence

She was breathing oxygen through a tube.

watched the liquid move through the tube between the flasks and recorded the movement in his chemistry notebook

Recent Examples on the Web

But the first third, yes, there are a lot of cathode ray tube TV screens. — Mike Ryan, IndieWire, 16 Oct. 2026

In August, the crew set a single-day CANDU record by fitting 20 tubes in 24 hours, beating the old mark of 16. — Aman Tripathi, Interesting Engineering, 16 Oct. 2026

Is an individual even a network, or is an individual just a genome, tiny little nuclei floating inside this tube? — Quanta Magazine, 15 Oct. 2026

Currently, there is only one optical tube, the Atlas 80, but Vaonis is planning to release add-on modules designed for looking at different night sky objects, including for planetary observation. — Harry Bennett, Space.com, 15 Oct. 2026

Word History

Etymology

French, from Latin tubus; akin to Latin tuba trumpet

First Known Use

1651, in the meaning defined at sense 1

Phrases Containing tube

• auditory tube
• breathing tube
• bronchial tube
• cathode-ray tube
• discharge tube
• down the tube
• electron tube
• endotracheal tube
• Eustachian tube
• Fallopian tube
• feeding tube
• flash tube
• image tube
• inner tube
• neural tube
• photomultiplier tube
• picture tube
• Pitot-static tube
• Pitot tube
• pollen tube
• shock tube
• sieve tube
• snow tube
• speaking tube
• static tube
• test tube
• test-tube baby
• the tube
• thistle tube
• torpedo tube
• tube foot
• tube nucleus
• tube pan
• tube sock
• tube top
• tube worm
• vacuum tube
• X-ray tube

Rhymes for tube

• boob
• cube
• lube
• rube
• hypercube
• nanotube
• phototube

Kids Definition

tube

noun

ˈt(y)üb 

1

a

: a slender channel within a plant or animal body : duct

b

: a long hollow cylinder

especially : one to carry fluids

c

: the part of a wind instrument that connects the mouthpiece with the open end

2

: a soft container shaped something like a tube whose contents (as toothpaste or glue) can be removed by squeezing

3

: inner tube

4

: electron tube

5

: television sense 2

6

: an article of clothing shaped like a tube

tube socks

tubed

ˈt(y)übd 

adjective

tubelike

ˈt(y)ü-ˌblīk 

adjective

Medical Definition

tube

1 of 2 noun

ˈt(y)üb 

1

: a slender channel within a plant or animal body : duct see bronchial tube, eustachian tube, fallopian tube

2

a

: an often complex piece of laboratory or technical apparatus usually of glass and commonly serving to isolate or convey a product of reaction

a distillation tube

b

: test tube

3

: a soft tubular container whose contents (as toothpaste) can be dispensed by squeezing

4

: a hollow cylindrical device (as a cannula) used for insertion into bodily passages or hollow organs for removal or injection of materials

tube

2 of 2 transitive verb

tubed; tubing

: to furnish with, enclose in, or pass through a tube

the patient is then anesthetized … and tubed

—Anesthesia Digest