man-to-man (m?n?t?-m?n?)adj.1. Marked by candid interaction between men: had a man-to-man talk with his boss.2. Sports Of, relating to, or being a system of defense in which a defensive player guards a specific offensive player.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.man-to-man adj characterized by directness or candour: a man-to-man discussion. Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014man?-to-man? adj. characterized by directness and openness; frank. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.