1809, "to strut" (swanky, n., "attractive young fellow" is recorded from 1508), perhaps related to Middle High German swanken "to sway, totter," and Old High German swingan "to swing." Said to have been a Midlands and southwestern England dialectal word. The noun meaning "ostentatious behavior" is recorded from 1854; adjective sense of "stylish, classy, posh" is from 1913.
: the swank of his riding clothes (1920s+)
To behave ostentatiously; strut: I saw her swanking up the avenue in furs (1809+)
[origin unknown; perhaps fr Middle English swanken, ''to sway,'' cognate with German schwenken, ''to flourish'']