What does siphon mean?
A siphon is a tube that moves liquid from a higher level to a lower one without requiring a pump. The device works because the pressure in the receiving container is lower than atmospheric pressure at the liquid surface, allowing gravity to draw the liquid through the tube. As a verb, “to siphon” means to transfer liquid in this way, as in siphoning fuel from a tank. It can also mean to drain or divert money, influence, customers, or other resources, usually with an implication of secrecy or unfairness. The word is common in both everyday and figurative contexts in British and American English. Its technical sense is chiefly used for plumbing, laboratory work, and liquid handling, while the figurative sense is especially frequent in news and business reporting. A siphon is different from a simple pipe because it carries liquid over a barrier and then downward.
A tube, pipe, or channel used to draw liquid from one place to another, especially from a higher level to a lower one.
"The bottle was fitted with a small siphon."
The technical sense is used in plumbing, engineering, chemistry, and laboratory work.
To draw or transfer liquid through a siphon; to drain or divert resources from one place or person to another.
"They siphoned water from the flooded basement into the garden."
Figurative uses often imply an improper or covert transfer.
The plural is used when referring to multiple siphon devices.
"The technician checked the siphons before starting the engine."
A siphon makes liquid travel uphill without a pump, using the pressure difference created by gravity and the atmosphere.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does siphon come from?
The word comes from Greek siphon, meaning “pipe” or “tube,” and entered English through Latin and French usage. The Greek term referred to a device that carries water upward and then lets it descend, a principle understood by ancient engineers. The English word developed both the physical meaning of a liquid-moving tube and the figurative meaning of withdrawing or diverting resources.
Related word forms
How siphon is actually used
In figurative use, “siphon” often has a negative connotation, suggesting an improper or covert diversion of resources. The spelling “syphon” is also widely recognized, but “siphon” is the standard modern form.
Easily confused with siphon
Syphon is an alternative spelling of siphon; it refers to the same tube or to the act of drawing off liquid through one.
A sip is a small quantity of liquid taken into the mouth, whereas a siphon is a device or action that transfers liquid from one place to another.