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siphon

American  
[sahy-fuhn] / ˈsaɪ fən /
Or syphon

noun

  1. a tube or conduit bent into legs of unequal length, for use in drawing a liquid from one container into another on a lower level by placing the shorter leg into the container above and the longer leg into the one below, the liquid being forced up the shorter leg and into the longer one by the pressure of the atmosphere.

  2. siphon bottle.

  3. a projecting tubular part of some animals, especially certain mollusks, through which liquid enters or leaves the body.


verb (used with or without object)

  1. to convey, draw, or pass through or as if through a siphon (sometimes followed by off ).

    to siphon water; to siphon off profits into a secret bank account.

siphon British  
/ saɪˈfɒnɪk, ˈsaɪfən /

noun

  1. a tube placed with one end at a certain level in a vessel of liquid and the other end outside the vessel below this level, so that liquid pressure forces the liquid through the tube and out of the vessel by gravity

  2. See soda siphon

  3. zoology any of various tubular organs in different aquatic animals, such as molluscs and elasmobranch fishes, through which a fluid, esp water, passes

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (often foll by off) to pass or draw off through or as if through a siphon

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
siphon Scientific  
/ sīfən /
  1. A pipe or tube in the form of an upside-down U, filled with liquid and arranged so that the pressure of the atmosphere forces liquid to flow upward from a container through the tube, over a barrier, and into a lower container.

  2. A tubular animal part, as of a clam, through which water is taken in or expelled.


Other Word Forms

  • pseudosiphonal adjective
  • pseudosiphonic adjective
  • siphonage noun
  • siphonal adjective
  • siphonic adjective
  • siphonless adjective
  • siphonlike adjective

Etymology

Origin of siphon

1650–60; < Latin sīphōn- (stem of sīphō ) < Greek síphōn, sī́phōn pipe, tube

Explanation

A siphon is a device used to move liquid from one container to the other. If you're giving your goldfish a magnificent new bowl, you can use a siphon to move the water from the old one to the new. A siphon is a tube running from one container to another that uses gravity to cause liquid to flow. The key is that the container with the liquid has to be at a higher level than the container you’re moving the liquid to. You have to use force to start the initial flow, but after that gravity takes over. We also use siphon as a verb, for the process of emptying. An endless meeting might siphon off all your energy.

Keep Reading on Vocabulary.com

Vocabulary lists containing siphon

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

As just one example, a Treasury advisory committee has estimated that payment stablecoins, which may be issued by all sorts of nonbanks, could siphon off $6.6 trillion of bank deposits.

From Barron's • Dec. 19, 2025

The alleged scam, and others like it, led to extensive soul-searching by streaming services on how to better protect artists from people abusing AI to siphon off royalty payments.

From MarketWatch • Oct. 16, 2025

Now, a slew of LNG terminals are under construction and set to siphon prodigious amounts of natural gas.

From The Wall Street Journal • Oct. 13, 2025

Corruption can siphon funds meant for health infrastructure, drug procurement or service delivery.

From Salon • Jul. 1, 2025

Several nights later, the scene was identical except that the moon had waned to a sliver and the siphon was pouring liquid back into the jugs left half full of Velma T.’s elixir.

From "Moon Over Manifest" by Clare Vanderpool