Definition of psi
: the 23rd letter of the Greek alphabet — see alphabet table
From the M-W Editors
Origin and Etymology of psi
Middle English, from Medieval Latin, from Late Greek, from Greek psei
First Known Use: 15th century
Origin and Etymology of psi
probably by shortening & alteration from psychic
First Known Use: 1942
3
psi
abbreviation
Definition of psi
pounds per square inch
Medical Dictionary
adjective
\ˈsī\
Medical Definition of psi
: relating to, concerned with, or being parapsychological psychic events or powers psi phenomena
2
psi
noun
Medical Definition of psi
: psi events or phenomena
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