ashlar masonry, the joints of which are worked with grooves, or channels, to render them conspicuous. Sometimes the whole of the joints are worked in this way, and sometimes only the horizontal ones. The grooves are either molded or plain, and are formed in several different ways. The surface of the work is sometimes left, or purposely made, rough, but at the present day it is usually made even. Rustic work was never employed in mediaeval buildings, but it is said to have had its origin in the buildings of Augustus and Claudius at Rome. — Parker, Gloss. of Architect. s.v.