Green’s Dictionary of Slang

1. an exquisitely well-dressed, fashionable person, although the implication is that beyond such perfection lies little else.

1850		T. Carlyle Latterday Pamphlets iii 37: ITom and Jack have been at least workers all their days, not idlers, game-preservers and mere human clothes-horses .
1889		‘Mark Twain’ Connecticut Yankee xxxiii. 378: I could see her [i.e. England] erect statues and monuments to her unspeakable Georges and other royal and noble clothes-horses.
1893		Progress (Shreveport, LA) 14 Oct. n.p.: Loie Fuller has metamorphosed the science of the evening dress [...] the woman is merely the [...] animated clotheshorse who interposes her energy into this climax of gorgeousness.
1894		Truth (Sydney) 14 Jan. 1/4: ‘He called me an ass,’ exclaimed an over-dressed, excited masher. ‘Well you ain’t one,’ soothingly replied a kindly companion, ‘you are only a clothes-horse’.
1903		Goodwin’s Wkly (Salt Lake City, UT) 3 Oct. 8/3: William Faversham seems destined to become the popular ‘clotheshorse’ of the county. [He] gained some attention last year by appearing in adress suit of light gray.
1910		University Missourian (Columbia, MO) 6 Sept. 2/2: Height in women has nothing to do wioth beauty[...] I don’t care for the fussy type of showgirl — the tall, cold clotheshorse.
1925		Black Mask Aug. III 9: The clothes-horse behind the curtain sure was getting one earful.
c.1930		(ref. to 1868) N. Kimball Amer. Madam (1981) 62: She got me [...] garters with red bows. Charlie said I was a clothes horse.
1939		W. Winchell On Broadway 20 Jan. [synd. col.] Lucius Beebe, a male clothes horse who regards clothes the way ordinary people regard bread.
1947		D. Burley N.Y. Amsterdam News 11 Oct. 23: The po’ clothes hosses found themselves all togged out for no avail.
1953		S. Bellow Augie March (1996) 130: Mr. and Mrs. Renling [...] made a clotheshorse out of me [...] picking out the tweeds and flannels, plaids, foulards, sport shoes [etc.].
1967		in S. Harris Hellhole 193: I’m a bit of a clothes horse [...] sort of glamorous.
1972		R. Barrett Lovomaniacs (1973) 106: I could turn into some kind of a spend-crazy clotheshorse.
1988		M. Atwood Cat’s Eye (1989) 215: His scorn for boys who give a hoot about how they look is devastating. He calls them fruity clothes-horses.
1996		P. Beatty White Boy Shuffle 63: The clotheshorses stood as much chance of being on a remedial track as the bummy kids with brown bag lunches.
1999		Guardian Guide 22–28 May 69: A consummate gambler, singer, comedian, clothes horse, [...] and adulterer.
2000		Indep. on Sun. Culture 14 May 18: The clothes-horse bought it on the Peripherique.
2012		T. Piccirilli Last Kind Words 175: He was a clothes horse. He had at least twenty tailored suits in his closet.

2. (also cloth horse) a fashion model.

1939		‘Ellery Queen’ Dragon’s Teeth 97: It was that woman back there [...] ex-clotheshorse!
1942		Berrey & Van Den Bark Amer. Thes. Sl. §574.7: Clothes horse, a woman who acts as a clothes model.
1950		M. Spillane Vengeance Is Mine 31: The agency is divided into two factions [...] the clotheshorses and the no-clotheshorses.
1950		Pittsburgh Courier (PA) 4 Mar. 20/1: Lovely model Mary Cunningham [has] become the first beige cloth horse for a downtown dress shoppe.
1984		P. Corris ‘Marriages Are Made in Heaven’ in Heroin Annie [e-book] The magazines were glossy, and the mirrors are fine if you’re a five foot nine clothes horse with the right angles and planes.
2001		Guardian Media 26 Feb. 3: Thus the celebrated clotheshorse became the first person to use the new legislation.