Green’s Dictionary of Slang

(US) of a woman, slatternly, unattractive.

1952		T.A.G. Hungerford Ridge and River (1966) 187: I’m lucky if I can sniff round some baggy little trull in a hick town.
1960		G. Swarthout Where the Boys Are 139: In Soho they’re baggy. In Mayfair they’re imported from France. They have a certain commercial smile.