linseed oil

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A yellowish oil extracted from the seeds of flax and used as a drying oil in paints and varnishes and in linoleum, printing inks, and synthetic resins.

from The Century Dictionary.

• noun A drying-oil produced by pressure from linseed, varying in color from light amber to dark yellow.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An oil, extracted from flax seeds, used as a drying agent in paints, varnishes etc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a drying oil extracted from flax seed and used in making such things as oil paints