mastic

noun

• 1 [mass noun] an aromatic gum or resin which exudes from the bark of a Mediterranean tree, used in making varnish and chewing gum and as a flavouring: incense made from sandalwood, eagle-wood, mastic and cloves

• 2 (also mastic tree) the bushy evergreen Mediterranean tree which yields mastic and has aromatic leaves and fruit, closely related to the pistachio.

  • Pistacia lentiscus, family Anacardiaceae
• used in names of trees that are similar or related to the mastic tree, e.g. American mastic.

• 3 [mass noun] a putty-like waterproof filler and sealant used in building: run a bead of mastic along the gap [as modifier]:a mastic sealant [count noun]:use a mastic between the joints