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

To preserve automatic ballot access, Shillings must pass that critical threshold in November — a prospect that could be made more difficult if Ballard gets on the ballot and siphons some Libertarian voters. —Marissa Meador, IndyStar, 24 Mar. 2026

Pascual demonstrated several tools used by coffee professionals, including a coffee siphon, a brewing method that uses heat and pressure, and a coffee refractometer, a device that measures how strong a cup of coffee is by analyzing how light refracts through the liquid. —Jonathan Myers, CBS News, 13 Mar. 2026

Verb

The rare collaboration underscores the severity of a concern raised by US AI companies that some users, especially in China, are creating imitation versions of their products that could undercut them on price and siphon away customers while posing a national security risk. —Bloomberg, Mercury News, 7 Apr. 2026

Many of Lamont’s fellow Democrats in the legislature’s majority argue Connecticut’s budget caps are too strict, siphoning too much money from core programs. —Keith M. Phaneuf, Hartford Courant, 2 Apr. 2026

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