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

Chris, Jesse, and Kendra all agree that Julia should start buying tomato paste in a tube, which lasts longer and is better suited to solo cooking. —Bon Appétit, 12 Feb. 2025

The provider inserts a flexible tube with a camera into the rectum and colon.6 During the colonoscopy, the provider looks for any abnormal signs, such as polyps (noncancerous growths) and inflammation. —Mark Gurarie, Health, 12 Feb. 2025

Thankfully, a largely untouched tube of Jones Road brow gel that lay at the bottom of my bag came to the rescue. —Kiana Murden, Vogue, 12 Feb. 2025

Schwartz added some artificial moondust—regolith—to certain organoid tubes to approximate its impact combined with that of radiation. —Dhruv Khullar, The New Yorker, 10 Feb. 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