From Longman Dictionary of Contemporary Englishsmugsmug /smʌɡ/ adjective PROUDshowing too much satisfaction with your own cleverness or success – used to show disapproval SYN self-satisfiedsmug about What are you looking so smug about?smug expression/look/face/smile etc ‘I knew I’d win, ’ she said with a smug smile.► see thesaurus at proud —smugly adverb —smugness noun [uncountable]
Examples from the Corpus
smug• Peter Kemp's aim seems to be to make Wells sound smug.• Frank patted his pocket and smiled, looking awfully smug.• I felt very smug about not wasting paper.• Lawson comes over as smug and arrogant, but in fact he's quite a decent man.• Daley was almost smug as he watched King floundering.• If you knew, which I'm sure you did judging from your smug expression, why didn't you tell me?• a smug grin• And Katie would give a smug little smile and then whisper about it half the night.• His was the smug look of a man who knew he was in total control and liked it that way.• Not to be a trifle smug, or anything.• Of all the mechanisms which sustain him in that feeling of smug self-satisfaction with himself, the chief one is self-justifying.smug expression/look/face/smile etc• His was the smug look of a man who knew he was in total control and liked it that way.• I close the window again with a smug smile on my face, and wait for the next battalion of eager buzzers.Origin smug (1500-1600) Probably from Low German smuck “pretty” 