non·ox·y·nol-9 (n?n-?k?s?-nôl?n?n?, -n?l?-, -n?l?-)n. A spermicide widely used in contraceptive creams, foams, and lubricants.[non(ane), alkane having nine carbons (from Latin n?nus, ninth; see noon) + (eth)oxy + (etha)nol + 9 (from from its chain of nine ethoxy groups).]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.