psi

1 of 3

noun (1)

ˈsī  ˈpsī 

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

psi

2 of 3

noun (2)

ˈsī 

: parapsychological psychic phenomena or powers

psi

3 of 3

abbreviation

pounds per square inch

Examples of psi in a Sentence

Recent Examples on the Web

Noun

Just to give you some perspective, the bite force of a measly human is just 162 psi. —Sara Novak, Discover Magazine, 27 Sep. 2024

By the time the Dragon's cabin was in a vacuum, the pressure inside the astronauts's suits was about 5 psi, which is slightly less than the summit of Mount Everest. —Eric Berger, Ars Technica, 12 Sep. 2024

The trick is to lower your tire pressure to 15 pounds per square inch (psi) or less. —Wes Siler, Outside Online, 31 May 2021

So even with a trio of electric motors and a battery pack, plus the beefy V8 and its two gigantic turbochargers capable of pushing up to 36.2 psi of boost, the new Lambo still only weighs 3,725.8 pounds. —Michael Teo Van Runkle, Forbes, 17 Aug. 2024

Word History

Etymology

Noun (1)

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

Noun (2)

probably by shortening & alteration from psychic

First Known Use

Noun (1)

15th century, in the meaning defined above

Noun (2)

1942, in the meaning defined above

Phrases Containing psi

• J/psi particle
• psi particle

Kids Definition

psi

noun

ˈsī

: the 23rd letter of the Greek alphabet

—Ψ or ψ

Medical Definition

psi

1 of 2 adjective

ˈsī 

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

psi phenomena

psi

2 of 2 noun

: psi events or phenomena