methyl salicylate

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

• noun The methyl ester of salicylic acid, C₈H₈O₃, an essential oil derived from birch or wintergreen or made synthetically, used as a counterirritant in ointments to treat muscle pain.

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

• noun chemistry The methyl ester of salicylic acid and the principal constituent of oil of wintergreen

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

• noun a liquid ester with a strong odor of wintergreen; applied externally for minor muscle and joint pain