wool grease

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

• noun A fatty, pale yellow wax that coats the fibers of sheep's wool and yields lanolin.

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

• noun Lanolin.

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

• noun a yellow viscous animal oil extracted from wool; a mixture of fatty acids and esters; used in some ointments and cosmetics