c. 1400, "proprietor, one who possesses or holds the title to a thing," also "worldly person, person tied to worldly goods or personal comforts," from noun uses of Old French proprietaire and Medieval Latin proprietarius "of a property owner" (see proprietary (adj.)). From 1630s in reference to the American colonies, "grantee or owner of a colony" (called proprietary colonies in distinction from charter colonies and royal colonies or provinces.
mid-15c., of clerics, "possessing worldly goods in excess of needs," from Medieval Latin proprietarius "owner of property," noun use of Late Latin adjective proprietarius "of a property holder," from Latin proprietas "ownership; a property" (see property). Meaning "held in private ownership, belonging to an owner" is attested from 1580s.
mid-15c., "renunciation of worldly goods," from Medieval Latin expropriationem (nominative expropriatio), noun of action from past-participle stem of Late Latin expropriare "deprive of property," from ex "away from" (see ex-) + propriare "take as one's own," from proprius "one's own" (see proper). Sense of "a taking of someone's property," especially for public use, is from 1848; as Weekley puts it, "Current sense of organized theft appears to have arisen among Ger. socialists."
"in the matter of, in the (legal) case of," c. 1600, probably from Duns Scotus; Latin, from re, ablative of res "property, goods; matter, thing, affair," from Proto-Italic *re-, from PIE *reh-i- "wealth, goods" (source also of Sanskrit rayi- "property, goods," Avestan raii-i- "wealth").