late 14c., "pertaining to a province," originally ecclesiastical, in reference to the jurisdiction of an archbishop or the districts of orders of friars, from Old French provincial "belonging to a particular province (of friars)" (13c.), from Latin provincialis "of a province," from provincia (see province).
Meaning "of the small towns and countryside" (as opposed to the capital and urban center) is from 1630s, a borrowed idiom from French, transferred from sense of "particular to the province," hence "local." Suggestive of rude, petty, or narrow society ("characteristic of or exhibiting the manners of the inhabitants of small towns and the countryside") by 1755. Classical Latin provincialis seems not to have had this tinge. In British use, with reference to the American colonies, from 1680s.