psi

¹ American  

Or p.s.i.

1. pounds per square inch.

---

psi ² American  

[sahy, psahy] / saɪ, psaɪ /

noun

• psis
  plural

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

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

---

psi ³ American  

[sahy] / saɪ /

noun

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

---

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

---

psi ² British  

abbreviation

1. pounds per square inch

---

Other Word Forms

Noun Inflected Forms

• psis
  plural

Etymology

Origin of psi²

1350–1400; Middle English < Greek pseî

Origin of psi³

1940–45; shortening of psychic or parapsychic

Example Sentences

See Examples For:

psi psis

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

Avoid them by setting your tire pressure low, never more than 5 psi.

From Seattle Times ● Dec. 9, 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

Though some psi studies continue today, most major universities have ended their programs due to inconsistent findings, lack of usefulness, or outright fraud.

From "American Spirits" by Barb Rosenstock

The important question had always been whether Lefty and the others were psis.

From Card Trick by John Berryman

Black tossed fitfully on the bed, seeking sleep desperately, seeking to escape the black night pressing in, to evade the imagined—or was it real?—probing minds of service psis.

From The Psilent Partner by John Victor Peterson

They weren't numerous; the Business Ethics Bureau which employed at least sixty percent of the known psis showed thirty on the payroll for this fiscal year.

From The Psilent Partner by John Victor Peterson

In fact, service psis are forbidden to associate with non-service psis.

From The Psilent Partner by John Victor Peterson

Pheola of the race-horse legs joined us, and several other psis as well.

From Card Trick by John Berryman