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

---

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.

---

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

Software stocks are finally making a tentative comeback after being pummeled by fears that artificial intelligence could siphon business away.

From Barron's • Mar. 4, 2026

Health and Human Services Secretary Xavier Becerra, to siphon funds from Becerra’s dormant state campaign account between February 2022 and September 2024.

From Los Angeles Times • Dec. 4, 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

It looks like she’s trying to siphon water out of their irrigation system, but that’s not going to work.

From "Dry" by Neal Shusterman and Jarrod Shusterman