bu·pre·nor·phine (byo?o?pr?-nôr?f?n?)n. A semisynthetic opioid drug, C29H41NO4, used usually in its hydrochloride form as an analgesic and, in combination with naloxone, for long-term treatment of addiction to opioids such as heroin.[bu(tyl) + pr(opyl) + en(do-) or (eth)en(e) + (m)orphine.]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.buprenorphine (bju??pr?n??fi?n) n (Medicine) an opiate used medicinally as a powerful analgesicCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014