bed head or bed·head (b?d?h?d?)n. Slang Hair that is unkempt, matted, or tousled, especially from being compressed or disheveled during sleep.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.bedhead (?b?dh?d) or bed-headnBrit a board fixed to the end of the bed behind one’s headCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014