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.

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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

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verb

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

siphon Scientific  

/ sī′fən /

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.

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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.

Example Sentences

The longer this money resides in your sister’s bank account, the more opportunity she will have to siphon it away or spend it.

From MarketWatch • Feb. 11, 2026

The acquisition comes at a key moment in the payments world, as fintech and crypto firms threaten to siphon business away from banks.

From The Wall Street Journal • Jan. 22, 2026

But for anyone who’s tangled with an eating disorder — and the way its tendrils quietly siphon joy from even the simplest routines — it is something.

From Salon • Jan. 1, 2026

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

Seriously, I have no idea where Mr. Neely finds all his excitement, but I wish I could siphon some of it off and give it to Mom.

From "The Science of Breakable Things" by Tae Keller