psi

noun (1)
\ ˈsī How to pronounce psi (audio) , ˈpsī How to pronounce psi (audio) \

Definition of psi

 (Entry 1 of 3)

: the 23rd letter of the Greek alphabet — see Alphabet Table

psi

noun (2)
\ ˈsī How to pronounce psi (audio) \

Definition of psi (Entry 2 of 3)

: parapsychological psychic phenomena or powers

Definition of psi (Entry 3 of 3)

pounds per square inch

First Known Use of psi

Noun (1)

15th century, in the meaning defined above

Noun (2)

1942, in the meaning defined above

History and Etymology for psi

Noun (1)

Middle English, from Medieval Latin, from Late Greek, from Greek psei

Noun (2)

probably by shortening & alteration from psychic

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Time Traveler for psi

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The first known use of psi was in the 15th century

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Dictionary Entries Near psi

pshaw

psi

PSIA

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Cite this Entry

“Psi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/psi. Accessed 17 May. 2022.

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More Definitions for psi

psi

adjective
\ ˈsī How to pronounce psi (audio) \

Medical Definition of psi

 (Entry 1 of 2)

: relating to, concerned with, or being parapsychological psychic events or powers psi phenomena

psi

noun

Medical Definition of psi (Entry 2 of 2)

: psi events or phenomena

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