no-non·sense (n?-n?n?s?ns?, -s?ns)adj. Not tolerating irrelevancies; direct, efficient, and practical: the no-nonsense tones of a stern parent; plain, no-nonsense meals at a diner.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.no-nonsense (?n???n?ns?ns) adjsensible, practical, straightforward; without nonsense of any kind: a businesslike no-nonsense approach; a severe no-nonsense look. Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014no?-non?sense adj. serious; businesslike. [1925?30] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.