Exhibiting or feeling great or offensive satisfaction with oneself or with one's situation; self-righteously complacent: "the smug look of a toad breakfasting on fat marsh flies” ( William Pearson).
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.