provincialism

A regional word, phrase, pronunciation, or usage.

The condition of being provincial; lack of sophistication or perspective.

The act or an instance of placing the interests of one's province before one's nation.

That which characterizes a province or a provincial person; a certain narrowness or localism of thought or interest, or rudeness of manners, characteristic of the inhabitants of a province as distinguished from the metropolis, or of the smaller cities and towns as distinguished from the larger; lack of polish or enlightenment.

Specifically, a word or manner of speaking peculiar to a province; a local or dialectal term or expression.