The word Paradise, as the very image of a celestial garden, ultimately entered most European languages (cf. French
paradis, German
Paradies, Italian
paradiso, Latin
paradisus) via Greek παραδεισος [
paradeisos]. However, its Persian origin is more of a political concept rather than its later (religious) derivations. Etymologically, the very root of the word can be traced in the Old Persian term
pairi-daêzã. It is combined of two parts: ‘pairi’ (cf. Sanskrit pįri, Greek περι), which literally means ‘around’, and ‘daêzã’ as ‘pile or heap’. The second part, however, is the origin of the words ‘دژ’ [
dezh] or ‘diza’, in modern Persian all stand for ‘fort’ or ‘enclosure’. ‘Daeza’ also has another root in the Indo-Iranian verb ‘dhaizh’ that originally means ‘to construct out of earth’, and the noun ‘dhaizha’, ‘that which has been built out of earth’.
Source:
http://thecityasaproject.org/2011/07/paradise/