chin-up (ch?n??p?)n. The act or an instance of chinning oneself, practiced especially as a fitness exercise. Also called pull-up.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.chin-up n (Gymnastics) an exercise in which a person grips an elevated bar and pulls himself or herself up until the chin is level with the bar Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014chin?-up` n. an act or instance of chinning a horizontal bar or the like. [1880?85] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.