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

The device is claimed to be +- 0.7% accurate from 0 to 39 psi, and +- 1.4% accurate from 40 to 85 psi, with 0.1 psi precision. —Ben Coxworth, New Atlas, 3 Nov. 2024

As with most fat tire bikes, handling is a bit vague, but airing the balloon tires up to near their maximum of 20 psi adds a bit of sharpness and speed while the full suspension keeps the ride plush. —William Roberson, Forbes, 28 Oct. 2024

Both have a maximum pumping capacity of 80 psi (5.5 bar) – the Large just gets there faster than the Regular. —New Atlas, 24 Oct. 2024

At the beginning of cabin depressurization on Thursday morning, the cabin pressure was 8.6 psi, slightly higher than the air pressure at the base camp at Mount Everest. —Eric Berger, Ars Technica, 12 Sep. 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