Psi

Pronunciation

• enPR: psÄ«, IPA: /psaɪ/, /saɪ/
• all for the latter pronunciation only
• Rhymes: -aɪ

• enPR: sÄ«, IPA: /saɪ/
• Rhymes: -aɪ

From Ancient Greek ψῖ, the name for the twenty-third letter of the alphabet (Ψ, ψ).

Full definition of psi

Noun

1. (countable) The twenty-third letter of Classical and Modern Greek and the twenty-fifth letter of Old and Ancient Greek.
2. (uncountable, parapsychology) A form of psychic energy.
• 1993, Will Self, My Idea of Fun:‘Come, lad,’ he said. ‘We will take tea together and speak of the noumenon, the psi and other more heterogenous phenomena.’

Initialism

Alternative forms

• P.S.I.
• PSI

{{initialism-old|en}}

1. Pounds per square inch an imperial unit of pressure

Anagrams

• IPS, IPs, ISP, pis, sip