Green’s Dictionary of Slang

lot of, a adj.

[abbr. SE whole lot of]

(US black) exceptionally good, skilful, esp. of musical ability.

[US] in R.S. Gold Jazz Lex. (1964) 195: ‘Damn,’ said Harry, ‘that’s a lot of horn, that really is.’.
[US]W.D. Overholser Fabulous Gunman 38: ‘You’re a lot of woman,’ he said.
[UK]D. Hamilton Death of a Citizen 119: It was a lot of car. Not only did it have the power [...] but it was steady as a rock.
T. Wicker Facing the Lions 169: A hell of a lot of woman. [...] You made me feel like a lot of woman, you know?
in L. Lamour Four Novels 238: And that was a lot of woman, too. Slim, but graceful and with a lot of spirit and heart.