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psi 1

 (sī, psī, psē)
The 23rd letter of the Greek alphabet. See Table at alphabet.

[Middle English, from Late Greek, from Greek psei.]

psi 2

Parapsychological phenomena or abilities considered as a group.

[Shortening and alteration of parapsychological.]

psi 3

pounds per square inch


abbreviation for
(Units) pounds per square inch


1. (Letters of the Alphabet (Foreign)) the 23rd letter of the Greek alphabet (Ψ, ψ), a composite consonant, transliterated as ps
2. (Psychology)
a. paranormal or psychic phenomena collectively
b. (as modifier): psi powers.
3. (Alternative Belief Systems)
a. paranormal or psychic phenomena collectively
b. (as modifier): psi powers.


(saɪ, psaɪ)

n., pl. psis.
the 23rd letter of the Greek alphabet (Ψ, ψ).
[1350–1400; Middle English < Greek pseî]



of or pertaining to parapsychological manifestations or abilities.
[1940–45; shortening of psychic or parapsychic]


or p.s.i.,

pounds per square inch.


Pounds per square inch: a unit for measuring pressure. One PSI equals the pressure resulting from a force of one pound force acting over an area of one square inch. See pound.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.psi - a unit of pressure
pressure unit - a unit measuring force per unit area
2.psi - the 23rd letter of the Greek alphabet
Greek alphabet - the alphabet used by ancient Greeks
alphabetic character, letter of the alphabet, letter - the conventional characters of the alphabet used to represent speech; "his grandmother taught him his letters"


1 ABBR =pounds per square inchkg/cm²


2 [saɪ] NPL (= psychic phenomena) → fenómenos mpl paranormales


n no pl
(= letter)Psi nt
(= psychic phenomena)Psi nt
References in periodicals archive ?
the Co-Chairs of the PSI Board and the Head of the UNEP FI Secretariat.
Pressure ranges from 3 to 5000 psi with various input/output configurations.
Once a hire has been made, PSI test are used for employee development.
This approach helps to ensure that PSI comes up with standards and definitions that accurately reflect the market at that time.
Senator Lindsey Graham (R-SC) said of the company's decision, "I'm pleased to welcome PSI Group to South Carolina.
We would like to thank Karel Kohlik and the PSI workshops for their competent and fast help building the experiment.
Either can be calibrated for engineering units such as psi, tons, or force.
We look forward to serving PSI and the mainframe industry with market leading technology advancements while providing customers the ability to maintain and extend their existing investments in mainframe infrastructure.
It has a flex modulus of 142,000 psi, tensile yield strength of 3400 psi, and ARM impact strength (0.
The company is seeking damages based on the harm that IBM's conduct has caused and is causing to PSI, as well as an injunction and/or remedies to prevent IBM from harming PSI in the future.
5 psi resolution, 0 to 10,000 psi range, and quick disconnect.
Andy Hanner, a co-founder of Three Rivers and its Chief Executive Officer, has joined PSI as President of the South Carolina Division.