anabolic steroidn. Any of a group of synthetic steroid hormones that promote the storage of protein and the growth of tissue, sometimes used by athletes to increase muscle size and strength. Nonprescription sale of anabolic steroids was declared illegal in the United States in 1990.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.anabolic steroid n (Pharmacology) any of a group of synthetic steroid hormones (androgens) used to stimulate muscle and bone growth for therapeutic or athletic purposes Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014an?abol?ic ster?oid n. any of a class of steroid hormones, esp. testosterone, that promote growth of muscle tissue. [1960?65] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.