ˈpīˌnēn noun
( -s )
Etymology: International Scientific Vocabulary pin- (from Latin pinus pine) + -ene — more at pine
: either of two liquid isomeric unsaturated bicyclic terpene hydrocarbons C 10 H 16 derived from pinane and found in turpentine oils:
a. : the isomer having the ethylenic double bond as part of the ring system, occurring in many essential oils (as juniper oil and eucalyptus oil), constituting in either its dextrorotatory or levorotatory form the principal component of various turpentines, and used chiefly as a solvent and chemical intermediate (as in making camphor or terpineol) — called also alpha-pinene, 2-pinene
b. : nopinene