late Old English, "the garden of Eden," from Old French paradis "paradise, garden of Eden" (11c.), from Late Latin paradisus "a park, an orchard; the garden of Eden, the abode of the blessed," from Greek paradeisos "a park; paradise, the garden of Eden," from an Iranian source similar to Avestan pairidaeza "enclosure, park" (Modern Persian and Arabic firdaus "garden, paradise"), a compound of pairi- "around" (from PIE root *per- (1) "forward," hence "in front of, near, against, around") + diz "to make, to form (a wall)." The first element is cognate with Greek peri "around, about" (see per), the second is from PIE root *dheigh- "to form, build."
The Greek word was used by Xenophon and others for an orchard or royal hunting park in Persia, and it was taken in Septuagint to mean "the garden of Eden," and in New Testament translations of Luke xxiii.43 to mean "the Christian heaven, place where the souls of the righteous departed await resurrection" (a sense attested in English from c. 1200; extended from c. 1400 to the Muslim heaven). Meaning "place of extreme beauty, blissful state like or comparable to Paradise" is from c. 1300. The Gates of Paradise originally meant "the Virgin Mary" (late 14c.)