/rus'ti kay"sheuhn/ , n.
1. Also called rustic work . Archit. any of various forms of ashlar so dressed and tooled that the visible faces are raised above or otherwise contrasted with the horizontal and usually the vertical joints.
2. the act of a person or thing that rusticates.
[ 1615-25; rustication- (s. of rusticatio ). See RUSTICATE, -ION ]