psi

¹ American  

Or p.s.i.

1. pounds per square inch.

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psi ² American  

[sahy, psahy] / saɪ, psaɪ /

noun

plural

psis

1. the 23rd letter of the Greek alphabet (Ψ, ψ).

2. the group of consonant sounds represented by this letter.

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psi ³ American  

[sahy] / saɪ /

noun

1. any purportedly psychic phenomenon, as psychokinesis, telepathy, clairvoyance, or the like.

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psi ¹ British  

/ psaɪ /

noun

1. the 23rd letter of the Greek alphabet (Ψ, ψ), a composite consonant, transliterated as ps

2. 1. paranormal or psychic phenomena collectively

   2. ( as modifier )

      psi powers

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psi ² British  

abbreviation

1. pounds per square inch

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Etymology

Origin of psi²

1350–1400; Middle English < Greek pseî

Origin of psi³

1940–45; shortening of psychic or parapsychic

Example Sentences

They were tested at halftime and found to be inflated to 11 psi, the website reported, instead of the league-mandated minimum of 13.5 psi.

From Washington Times • Dec. 21, 2023

Such an amount is greater than the bite pressure exerted by some of the strongest jaws in the animal kingdom: Crocodile bites have been measured at up to 3,700 psi.

From Scientific American • Jun. 21, 2023

To qualify for the grand prize, divers must finish with 750 psi or more in their tank.

From Seattle Times • Oct. 26, 2022

If pressure after the reducing valve is low, which generally means below 40 psi, Ray installs a new valve, and that often solves the problem.

From Washington Post • Apr. 25, 2022

Taken together, topics like these are known as psi, the scientific study of “processes of information or energy transfer that are currently unexplained in terms of known physical or biological mechanisms.”

From "American Spirits" by Barb Rosenstock