Green’s Dictionary of Slang

1. (US teen) an attractive woman.

1943		Chicago Trib. Graphic Section 26 Dec. 7/1: Jive Talk [...] Smooth Girl Slick chick. Sweet stuff. Wolf bait. Queen of hearts. P-38. Able Grable. A good deal. A doll. Smooth potato. Hot gingerbread. Pretty pigeon. 20-20 little squab.
1944		Carroll Dly Times (IA) 11 Dec. 3/4: Found: An able Grable who’s Betty Rosenbaum’s cousin from Missouri Valley.
1945		Yank (Far East edn) 24 Mar. 18/2–3: Some of today’s teen-agers – pleasantly not many – talk the strange new language of ‘sling swing.’ In the bright lexicon of the good citizens of tomorrow, a girl with sex appeal is an ‘able Grable’ or a ‘ready Hedy’.

2. (US) an accomplished performer.

1946

Dly Trib. (Wisconsin Rapids, WI) 16 Apr. 3/1: Clarion Peterson, a very ‘able Grable’ on the accordion.