Definition of psi
(Entry 1 of 3)
: the 23rd letter of the Greek alphabet — see Alphabet Table
psi
noun (2)Definition of psi (Entry 2 of 3)
: parapsychological psychic phenomena or powers
psi
abbreviationDefinition of psi (Entry 3 of 3)
pounds per square inch
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Merriam-Webster unabridged
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Time Traveler for psi
The first known use of psi was in the 15th century
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