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

Verb

• pump
• drain

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

Soda makers, on the other hand, can carbonate much more water than a siphon, as the carbon dioxide cartridge is inside the machine to create carbonated water. —Bestreviews, Mercury News, 27 May 2025

The basalt siphons slowed the destruction, to an extent, but in February 2024, lava outflows disabled a network of pipes from the power station. —Jonah Walters, Longreads, 24 Oct. 2024

Verb

OPMs typically take 50–60% of tuition revenue in exchange for upfront marketing and tech investments—a deal that siphons resources away from educational quality. —Scott White, Forbes.com, 17 June 2025

Desperation grows as rival aid systems can’t meet needs Israel says the new system operated by a private contractor, the Gaza Humanitarian Foundation, is designed to prevent the militant group Hamas from siphoning off aid to fund its activities. —Mohammad Jahjouh, Los Angeles Times, 17 June 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