oleic acid

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

• noun An oily liquid monounsaturated fatty acid, C₁₈H₃₄O₂, occurring in animal and vegetable oils and used in making soap.

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

• noun organic chemistry An unsaturated fatty acid, having 18 carbon atoms and one double bond, found in olive oil and very many other vegetable and animal oils and fats; it is used for making soap, cosmetics etc.

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

• noun a colorless oily liquid occurring as a glyceride; it is the major fatty acid in olive oil and canola oil; used in making soap and cosmetics and ointments and lubricating oils