siphon

1 of 2

noun

si·​phon ˈsī-fən 

variants or less commonly syphon

1

a

: a tube bent to form two legs of unequal length by which a liquid can be transferred to a lower level over an intermediate elevation by the pressure of the atmosphere in forcing the liquid up the shorter branch of the tube immersed in it while the excess of weight of the liquid in the longer branch when once filled causes a continuous flow

b

usually syphon : a bottle for holding aerated water that is driven out through a bent tube in its neck by the pressure of the gas when a valve in the tube is opened

2

: any of various tubular organs in animals and especially mollusks or arthropods that are used for drawing in or ejecting fluids

Illustration of siphon

• siphon 1a

siphon

2 of 2

verb

variants or less commonly syphon

siphoned also syphoned; siphoning also syphoning ˈsī-fə-niŋ 

ˈsīf-niŋ

transitive verb

: to convey, draw off, or empty by or as if by a siphon

—often used with off

intransitive verb

: to pass by or as if by a siphon

Synonyms of siphon

Verb

• drain
• pump

Examples of siphon in a Sentence

Verb

The water needs to be siphoned from the pool.

She illegally siphoned money out of other people's bank accounts.

Funds were siphoned from the schools to build a new stadium.

The large chain stores are siphoning profits from the small local stores.

Recent Examples on the Web

Noun

Democrats and other critics argue the program siphons away tax dollars from local school districts, forcing communities to increase property taxes. —Center Square, The Washington Examiner, 18 Dec. 2025

The mussels have even started appearing on irrigation siphons that pipe Delta water onto farmland. —Calmatters, Mercury News, 6 Nov. 2025

Verb

Israel has said throughout the war that Hamas was siphoning off aid supplies, an accusation that the United Nations and aid groups have denied. —Wafaa Shurafa, Los Angeles Times, 2 Jan. 2026

Most of them run on some of the dirtiest fuel in the world, the leftover gunk after all the other useful parts are siphoned off to make gasoline and other more valuable petroleum products. —Miami Herald, 31 Dec. 2025

Word History

Etymology

Noun

French siphon, from Latin siphon-, sipho tube, pipe, siphon, from Greek siphōn

First Known Use

Noun

1659, in the meaning defined at sense 1a

Verb

1859, in the meaning defined at transitive sense

Rhymes for siphon

• hyphen
• syphon
• typhon

Kids Definition

siphon

1 of 2 noun

si·​phon

variants also syphon

ˈsī-fən

1

: a bent tube through which a liquid can be drawn by means of air pressure up and over the edge of one container and into another container at a lower level

2

: any of various tube-shaped organs in animals and especially mollusks that are used to draw in or pass off fluids

siphon

2 of 2 verb

variants also syphon

siphoned also syphoned; siphoning also syphoning

ˈsīf-(ə-)niŋ

: to draw off or pass off by or as if by a siphon

siphoned off money for a vacation