si·phon | \ˈsī-fən \
variants: or less commonly

Definition of siphon 

(Entry 1 of 2)

1a : 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


variants: or less commonly syphon
siphoned also syphoned; siphoning also syphoning\ˈsī-fə-niŋ, ˈsīf-niŋ \

Definition of siphon (Entry 2 of 2)

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

Illustration of siphon

Illustration of siphon


siphon 1a

In the meaning defined above

Keep scrolling for more

Synonyms & Antonyms for siphon

Synonyms: Verb

bleed, draft, drain, draw (off), pump, tap

Antonyms: Verb


Visit the Thesaurus for More 

Examples of siphon in a Sentence


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.
See More

Recent Examples on the Web: Noun

Snails that had been shocked before retreated their siphons for longer than new snails. Laura Yan, Popular Mechanics, "Scientists Just Transferred Memories From One Creature to Another," 19 May 2018 The site is adjacent to a shaft containing multiple pipes used to lift sewage up to the plant from harbor siphons. Don Behm, Milwaukee Journal Sentinel, "Untreated sewage leaks from Jones Island into Kinnickinnic River and Milwaukee harbor," 12 Feb. 2018 If the animals were subject to other stresses—one option is to implant electrodes elsewhere and give them a bit of a shock—this reflex could be sped up and the siphon would get withdrawn for longer periods. John Timmer, Ars Technica, "Researchers claim to have transferred a memory between two sea slugs," 16 May 2018 Others said operation of the Mid-Barataria diversion should be part of a basin-wide plan to coordinate all diversions and water siphons to protect the health of the basin. Mark Schleifstein,, "Public wants Army Corps to look at Mid-Barataria diversion effects on fisheries, communities," 24 Jan. 2018 Painted on the walls are lessons on the evolution of Chemex brewing and the siphon pot. Mike Sutter, San Antonio Express-News, "Top 5 coffee shops in San Antonio," 4 June 2018 Yes, the Bay Area coffee chain has lost some of its luster since being acquired by big bad Nestle, but there’s still something magical about sitting at the bar at the Mint Plaza location and watching the siphon-style coffee prepared. Sarah Fritsche, San Francisco Chronicle, "Where to find unforgettable tea and coffee service in the Bay Area," 25 May 2018 Like the Seattle flagship, the Reserve coffee bars will brew drinks on machines including a siphon, and a Black Eagle espresso maker — the similar equipment staples at froufrou shops like Intelligensia. Jacqueline Colette Prosper, ELLE Decor, "Starbucks Reserve Quenches Hip Coffee Lovers' Thirst With 1,000 New Upscale Cafes," 21 Oct. 2016 The water starts getting sucked up the paper towel due to capillary action (described in the background section) and eventually starts going down the other side into the empty glass (just like a siphon). Ben Finio, Scientific American, "Walking Water," 3 May 2018

Recent Examples on the Web: Verb

Trump administration to dump Obama-era rule allowing unions to siphon Medicaid money. Fox News, "FOX NEWS FIRST: Anti-Trump FBI lovebird defies subpoena; Trump slams 'inappropriate' Russia deal at NATO summit," 11 July 2018 There is reason to be concerned about Kelce stealing red-zone looks and Hill siphoning off deep balls, two areas where Watkins can excel, but the good about his team context significantly outweighs the bad. Michael Beller,, "Old Faces in New Places: Fantasy Football Impact of the Biggest Offseason Moves," 6 July 2018 The startup’s valuation was dropping, fundraising was more difficult and Amazon was pledging $5 billion-plus to siphon away customers. Saritha Rai, The Seattle Times, "Flipkart CEO steered around Amazon to deliver Indian consumers to Walmart," 13 May 2018 The hackers began siphoning documents and information from DNC systems on April 22. The Washington Post,, "Democratic party sues Russia, Trump campaign, allege conspiracy to influence election," 20 Apr. 2018 The hackers began siphoning documents and information from DNC systems on April 22. The Washington Post,, "Democratic party files lawsuit against Russia, Trump campaign, alleging conspiracy to influence the election," 20 Apr. 2018 And water siphoned off the Sacramento River in the northern delta would be fresher than what’s pumped now from the more brackish southern region. George Skelton,, "What do Southern Californians really get out of Gov. Jerry Brown's twin tunnels project?," 12 July 2018 Turkey is siphoning off an ever-growing share of the Tigris and Euphrates to feed its growing population in a warming climate. Philip Issa, Fox News, "Iraq bans farming summer crops as water crisis grows dire," 5 July 2018 Turkey is siphoning off an ever-growing share of the Tigris and Euphrates to feed its growing population in a warming climate. Washington Post, "Iraq bans farming summer crops as water crisis grows dire," 5 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'siphon.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of siphon


1659, in the meaning defined at sense 1a


1859, in the meaning defined at transitive sense

History and Etymology for siphon


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

Keep scrolling for more

Learn More about siphon

Dictionary Entries near siphon








Statistics for siphon

Look-up Popularity

Time Traveler for siphon

The first known use of siphon was in 1659

See more words from the same year

Keep scrolling for more

More Definitions for siphon



English Language Learners Definition of siphon

 (Entry 1 of 2)

: a bent tube used to move a liquid from one container into another container by means of air pressure



English Language Learners Definition of siphon (Entry 2 of 2)

: to move (a liquid) from one container to another by using a siphon

: to take and use (something, such as money) for your own purpose


si·phon | \ˈsī-fən\

Kids Definition of siphon

 (Entry 1 of 2)

1 : a bent pipe or tube through which a liquid can be drawn by air pressure up and over the edge of a container

2 : a tubelike part especially of a mollusk (as a clam) usually used to draw in or squirt out water


siphoned; siphoning

Kids Definition of siphon (Entry 2 of 2)

: to draw off by or as if by a siphon

Keep scrolling for more

Comments on siphon

What made you want to look up siphon? Please tell us where you read or heard it (including the quote, if possible).


a state of commotion or excitement

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
True or False

Test your knowledge - and maybe learn something along the way.


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!