NSAID (?n?s?d?)n. A nonsteroidal anti-inflammatory drug, such as ibuprofen.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.NSAID abbreviation for (Pharmacology) nonsteroidal anti-inflammatory drug: any of a class of drugs, including aspirin and ibuprofen, used for reducing inflammation and pain in rheumatic diseases. Possible adverse effects include gastric ulceration Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014NSAID nonsteroidal anti-inflammatory drug. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.