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

psi

2 of 3

noun (2)

: 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
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 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 See all Example Sentences for psi 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'psi.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Time Traveler
The first known use of psi was in the 15th century

Dictionary Entries Near psi

Cite this Entry

“Psi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/psi. Accessed 5 Nov. 2024.

Kids Definition

psi

noun
ˈsī
: the 23rd letter of the Greek alphabet
Ψ or ψ

Medical Definition

psi

1 of 2 adjective
: relating to, concerned with, or being parapsychological psychic events or powers
psi phenomena

psi

2 of 2 noun
: psi events or phenomena
Last Updated: - Updated example sentences
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