psi
or p.s.i.
- pounds per square inch.
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psi1
[sahy, psahy]
- the 23rd letter of the Greek alphabet (Ψ, ψ).
- the group of consonant sounds represented by this letter.
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Origin of psi1
1350–1400; Middle English < Greek pseî
psi2
[sahy]
- any purportedly psychic phenomenon, as psychokinesis, telepathy, clairvoyance, or the like.
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Compare pseudoscience, parapsychology.
Origin of psi2
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for psi
Contemporary Examples
Will PSI (private sector involvement) become common in future bailouts?
In 2009, Judd lent her voice to a PSI World Malaria Day PSA.
The fraternities involved in the alleged drug sales were Alpha Epsilon Pi, Pi Kappa Alpha and Psi Upsilon.
PSI board member Ashley Judd is a celebrated actress, activist, and humanitarian.
Take Action: Ashley Judd works with the nonprofit PSI, investing in the power of women to lift communities out of poverty.
Historical Examples
We know the Auerbach cylinder will store a psi impulse, but we don't know how.
Sense from Thought DivideMark Irvin Clifton
I didn't need any psi talent for that, it was an inevitable part of his pattern.
Sense from Thought DivideMark Irvin Clifton
What we really lacked in psi was the ability to orient its phenomena.
Sense from Thought DivideMark Irvin Clifton
I could say psi was a flow of positrons, and it would mean as much.
Sense from Thought DivideMark Irvin Clifton
We were both trying to get hold of and benefit by psi effects, weren't we?
Sense from Thought DivideMark Irvin Clifton
psi1
- pounds per square inch
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psi2
- the 23rd letter of the Greek alphabet (Ψ, ψ), a composite consonant, transliterated as ps
- paranormal or psychic phenomena collectively
- (as modifier)psi powers
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for psi
n.
23rd letter of the Greek alphabet. Use for "psychic force, paranormal phenomenon" dates from 1942 (probably from psychic (adj.)).
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Online Etymology Dictionary, © 2010 Douglas Harper
psi
(sī, psī)- The 23rd letter of the Greek alphabet.
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The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.