psi

¹psi

noun \ˈsī, ˈpsī\

Definition of PSI

: the 23d letter of the Greek alphabet — see alphabet table

Origin of PSI

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

First Known Use: 15th century

Rhymes with PSI

ay, aye, bi, Bligh, buy, by, bye, chai, chi, cry, die, dry, dye, eye, fie, fly, fry, guy, hie, high, Huai, i, I, lie, lye, my, nigh, phi, pi, pie, ply, pry, rye, scythe, shy, sigh, sky, Skye, sly, spry, spy, sty, Tai, Thai, thigh, thy, tie, try, vie, why, wry, wye, xi, Y

²psi

noun \ˈsī\

Definition of PSI

: parapsychological psychic phenomena or powers

Origin of PSI

probably by shortening & alteration from psychic

First Known Use: 1942

³psi

abbreviation

Definition of PSI

pounds per square inch