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

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

Fortunately the firm employed a psi, one of the few known psis not in government service.

From The Psilent Partner by Peterson, John Victor

He knew, of course, what was commonly known—that they possessed wide and very varied talents, that they were categorized as plain psis, psi-espers, esper-psis, telepaths and other things.

From The Psilent Partner by Peterson, John Victor

The Government would never condone the deal Lawrence was contemplating—the Applied Atomics Corporation was nearly insolvent, the BEB psis were investigating it....

From The Psilent Partner by Peterson, John Victor

And they must surely realize that all mankind will evolve to psis one day.

From The Psilent Partner by Peterson, John Victor

He switched on the inner office instrument and a familiar face came in sync on the screen—that of Peter Dodson, the principal administrative officer of the BEB psis.

From The Psilent Partner by Peterson, John Victor