Thack·er·ay (th?k??-r?, th?k?r?), William Makepeace 1811-1863. British writer whose novels, including Vanity Fair (1848), explore the ethical and social pretensions of largely amoral characters.Thack?er·ay·an adj.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.