c.1290, from Anglo-Fr.
paroche (1292),
parosse (c.1075), from O.Fr.
paroisse, from L.L.
parochia "a diocese," alt. of Late Gk.
paroikia "a diocese or parish," from
paroikos "a sojourner" (in Christian writers), in classical Gk. "neighbor," from
para- "near" +
oikos "house" (see
villa). Sense development unclear, perhaps from "sojourner" as epithet of early Christians as spiritual sojourners in the material world. In early Church writing the word was used in a more general sense than Gk.
diokesis, though by 13c. they were synonymous. Replaced O.E.
preostscyr, lit. "priest-shire."
Parishioner is attested from 1471, outlasting its older doublet
parochian (c.1225), which was obs. by 1700.
[par-ish] 
ɪʃ