Definition
A volatile, flammable liquid solvent distilled from the resin (oleoresin) of pine trees, used historically as a thinner for oil-based paints, varnishes, and dopes applied to fabric-covered aircraft.
Plain English
A strong-smelling liquid made from pine tree sap. It dissolves and thins paints and varnishes, and it was commonly used on older fabric airplanes when applying finishes.
Context Anchor
Seen in aircraft finishing, restoration, paint, varnish, and shop-cleanup discussions.
Derivation
From the Greek 'terebinthos,' the name of the terebinth tree, which produces a similar resin. The word came into English through Latin and Old French. Knowing the origin reinforces that turpentine is a tree-resin product, not a synthetic chemical.
Why Pilots Care
Anyone working on older fabric aircraft or restoring vintage aircraft may encounter turpentine in finishing materials. It is flammable and produces strong fumes, so it must be stored, used, and disposed of carefully in a hangar environment.
Intuition Check
Do not assume turpentine is just a harmless household cleaner. In aircraft work, it is a flammable solvent that must match the material and the job.
Example Sentence 1
The mechanic thinned the varnish with a small amount of turpentine before brushing it onto the wooden propeller.
Example Sentence 2
Turpentine thinned the paint so it would flow evenly over the fabric-covered wing.