1 a gum or resin exuded from the bark of the mastic tree, used in making varnish.
2 (in full mastic tree) the evergreen tree, Pistacia lentiscus, yielding this.
3 a waterproof filler and sealant used in building.
4 a liquor flavoured with mastic gum.
Etymology: ME f. OF f. LL mastichum f. L mastiche f. Gk mastikhe, perh. f. mastikhao (see MASTICATE) with ref. to its use as chewing-gum
Useful english dictionary. 2012.