Pronunciation: (mas'tik),[key] —n. 1. Also called lentisk. a small Mediterranean tree, Pistacia lentiscus, of the cashew family, that is the source of an aromatic resin used in making varnish and adhesives.
2. any of several similar or related trees, as a pepper tree, Schinus molle, of western South America.
3. the resin obtained from the mastic.
4. any similar resin, esp. one yielded by other trees of the same genus.
5. Building Trades. a. any of various preparations containing bituminous materials and used as an adhesive or seal.
b. a pasty form of cement used for filling holes in masonry or plaster.