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

Phrases

down the tube or down the tubes

: into a state of collapse or deterioration

Synonyms

• channel
• conduit
• duct
• leader
• line
• penstock
• pipe
• trough

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

Authorities said a blast dislodged a tube attached to the hyperbaric chamber, which resulted in an explosion and flash fire, according to CBS. —Michael Dorgan, Fox News, 31 Jan. 2025

Also, the lower Guadalupe River begins at the Canyon Lake dam and winds through the Texas Hill Country to New Braunfels, allowing plenty of opportunities to rent a tube and float your way down the river, which also boasts beautiful water. —Kaitlyn Yarborough, Southern Living, 30 Jan. 2025

The big picture: The stealthy destroyer splashed back into the water after a retrofit that gave it four missile tubes to hold the Conventional Prompt Strike weapon. —Colin Demarest, Axios, 29 Jan. 2025

But the device is less intuitive than the current generation of high-end juicers, leafy greens required a bit of fiddling to push through the feeder tube, and the device struggled with fibrous vegetables such as pineapple and broccoli. —Matthew Korfhage, WIRED, 29 Jan. 2025

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
• 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

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