OXFORD DICTIONARY
dude, n. US sl.
1 a fastidious aesthetic person, usu. male; a dandy.
2 a holiday-maker on a ranch in the western US, esp. when unused to ranch life.
3 a fellow; a guy.
dude ranch a cattle ranch converted to a holiday centre for tourists etc.
dudish adj.
19th c.: prob. f. G dial. dude fool
THESAURUS
dude
Beau Brummel, beau, blade, blood, boulevardier, buck, chap, clotheshorse, coxcomb, dandy, exquisite, fashion plate, fellow, fine gentleman, fop, fribble, gallant, guy, jack-a-dandy, jackanapes, lady-killer, lounge lizard, macaroni, man, man-about-town, masher, popinjay, puppy, spark, sport, swell
ROGET THESAURUS
dude
Fop
N
fop, fine gentleman, swell, dandy, dandiprat, exquisite, coxcomb, beau, macaroni, blade, blood, buck, man about town, fast man, fribble, milliner, Jemmy Jessamy, carpet knight, masher,
dude, fine lady, coquette, flirt, vamp.