any of a class of solid or semisolid viscous substances obtained either as exudations from certain plants or prepared by polymerization of simple molecules
source: WordNet 3.0
Any one of a class of yellowish brown solid inflammable substances, of vegetable origin, which are nonconductors of electricity, have a vitreous fracture, and are soluble in ether, alcohol, and essential oils, but not in water; specif., pine resin (see Rosin).
