Green’s Dictionary of Slang

sexually attractive, sexually exciting; voluptuous.

1930		A.R.D. Fairburn letter in Edmond Letters (1981) 1 Feb. 31: Sounds meaty, don’t it?
1935		(con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 598: A girl whose slim, tall but meaty figure was wrapped in a stylish blue cloth coat.
1937–84		Partridge DSUE (1984) 730: from ca. 1820.
1976		R. Daley To Kill a Cop 172: She had big breasts and a meaty behind.