According to my dictionary "swank" and "swanky" came into general informal use in Britain during the 19C, and has a possible derivation from Middle High German "swanken", to sway.
jim wrote: According to my dictionary "swank" and "swanky" came into general informal use in Britain during the 19C, and has a possible derivation from Middle High German "swanken", to sway. My dictionary says to "swagger" and it's a colloquialism.Thanks for your answer, jim.