the word 'swanky' is a relatively modern english formation, emerging in the early 20th century. it derives from the earlier verb 'swank,' meaning to strut or behave in a showy, ostentatious manner, whose own origins are obscure but may be connected to germanic roots related to swinging or swaying. the addition of the productive adjectival suffix '-y,' of old english origin, transforms the action into a descriptive quality. thus, the literal sense of "characterized by swanking" evolved into its contemporary meanings describing things that are fashionably luxurious or people who are showily impressive.

Structure: swank + y swank (origin uncertain, possibly from germanic; meaning: to strut or show off) + y (old english suffix; meaning: characterized by or inclined to).