Definition from Wiktionary, the free dictionary
- (idiomatic, vulgar) A broad smile indicating self-awareness that may suggest self-satisfaction, smugness, discomfort, or embarrassment.
- The term is ambiguous and may indicate either a genuine broad smile (e.g. smug happiness) or a fake broad smile (e.g. trying to hide or get away with something).
- For more examples of usage of this term, see Citations:shit-eating grin.
broad smile of smugness
broad smile of embarrassment
- Oxford English Dictionary, 2nd ed., 1989.