linseed oil, amber-colored, fatty oil extracted from the cotyledons and inner coats of the linseed. The raw oil extracted from the seeds by hydraulic pressure is pale in color and practically without taste or odor. When boiled or extracted by application of heat and pressure, it is darker and has a bitter taste and an unpleasant odor. Linseed oil has long been used as a drying oil in paints and varnish. It is also used in making linoleum, oilcloth, and certain inks.