English Reference

Word

siphon

US/ˈsaɪfən/

UK/sˈaɪfən/

UK spelling · Syphon

Definitions

01a tube for moving liquid

B2

n. a tube shaped like a 'U' that uses gravity to pull liquid up and out of a container into a lower one.

n. a bent tube used to transfer liquid from a higher to a lower level by means of air pressure and gravity.

“He used a plastic siphon to empty the water out of the fish tank.”

“The mechanic inserted a flexible siphon into the fuel tank to drain the contaminated petrol before repairing the engine.”

Synonyms

02biological tube

C1 · Science

n. a tube-like part in some animals or plants used for moving water or air.

n. a tubular organ in certain invertebrates, such as molluscs, used for the intake or output of water.

“The clam uses its siphon to pull in water and filter out food.”

“Marine biologists observed the octopus using its siphon to expel a powerful jet of water, allowing it to propel itself away from the predator.”

Technical

Synonyms

03to move liquid

B2

v. to move liquid through a tube from one place to another.

v. to convey, draw off, or empty liquid by means of a siphon. Transitive, requiring a direct object.

“We had to siphon the water out of the basement after the heavy rain.”

“The wine was carefully siphoned from the fermentation vat into oak barrels to avoid disturbing the sediment at the bottom.”

04to take money dishonestly

C1

v. to gradually take money or resources from a business or account, often in a way that is not legal.

v. to divert or draw off resources, especially money, from a fund or account over a period of time, typically dishonestly.

“The manager was caught trying to siphon money from the company's bank account.”

“Investigators discovered that the executive had been siphoning millions into offshore accounts through a series of shell companies for over a decade.”

Informal

Synonyms

embezzledivertdrain

Real-World Examples

“Fryatt believes Ahmed’s motivation for his crime was simple: “Money, getting rich quick … There was no kind of siphoning it off and investing it.”
The Guardian · 19 Sept 2026
“It condemned illegal tapping and siphoning, warning that such activities put lives, the environment and the economy at risk.”
BBC News · 4 Sept 2026

Etymology

From Middle French siphon, from Old French sifon, from Latin sipho, from Ancient Greek σίφων (síphōn, “pipe, tube”), of uncertain origin; possibly related to Latin tibia (“pipe, flute of bone”), with the irregular forms suggesting a non-Indo-European loan source, perhaps of the shape twi-, twibh.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domains

BotanyZoology

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

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English Reference