O. Henry See William Sydney Porter.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.O. Henry (?? ?h?nr?) n (Biography) pen name of William Sidney Porter. 1862?1910, US short-story writer. His collections of stories, characterized by his use of caricature and surprising endings, include Cabbages and Kings (1904) and The Four Million (1906)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014