psi Definition and Meaning in English (psi definition)

Psi is a unit of pressure, commonly used to measure tire pressure or other fluid pressures, representing pounds of force per square inch.

Psi is the twenty-third letter of the Greek alphabet, represented by the uppercase symbol Ψ and lowercase symbol ψ.

In parapsychology, psi refers to psychic phenomena or abilities, such as telepathy, clairvoyance, or psychokinesis.