Green’s Dictionary of Slang

feisty adj.

also fisty
[SE fist, a small dog; thus having the characteristics of such a yappy, snappy, energetic creature; the dog shares an ety. with 15C fist, a foul smell, the breaking of wind, but whether, as Wentworth & Flexner suggest in Dict. American Slang (1960, 1975), the dog was so named because one’s own smells could be blamed upon it remains debatable. Equally feasible is the 19C suggestion that such dogs were not much bigger than a man’s fist. Note dial. feist, to strut about, to flirt or show off]

1. (orig. US) truculent, irascible, impertinent.

[US]DN I 372: Fisty low, mean, cross .
[US]DN II 313: Fisty [...] Impudent, self-important.
[US]H. Kephart Our Southern Highlanders (1922) 94: Feisty means when a feller’s allers wigglin’ about, wantin’ ever’body to see him, like a kid when the preacher comes.
[US]E.M. Roberts Time of Man 152: That-there feisty bay mare jumped straight upwards and broke the tongue outen the plow. But Sandy says he can fix it.
[US]Randolph & Wilson Down in the Holler 106: The adjective feisty, used in some parts of the South to mean saucy or truculent [etc].
[US]S. Longstreet Flesh Peddlers (1964) 260: The feisty little crud said you was a ...
[US]L.K. Truscott IV Dress Gray (1979) 437: ‘Oldest story in the book,’ she said. ‘Feisty old babe.’.
[US]N. Pileggi Wiseguy (2001) 6: She hoped that the after-school job might get her feisty young son out of the house long enough to keep him from bickering incessantly with his sisters.
[US](con. early 1950s) J. Ellroy L.A. Confidential 231: The desk sergeant told him the spooks were getting feistier.
[US]J. Stahl I, Fatty 225: Mrs. Hubbard, a feisty old haybag.

2. (orig. US) of a young woman, flirtatious (to a greater extent than the speaker sees as proper), showing off, putting on airs, of dubious morality; 1980s+ use tends to perceive this in a more positive light.

[US]J.W. Carr ‘Words from Northwest Arkansas’ in DN III:i 79: fisty, adj. Pert, impudent, conceited, meddling. ‘Don’t get fisty’.
[US]Randolph & Wilson Down in the Holler 106: The adjective feisty [...] is generally applied to females in the Ozarks and means flirtatious or provocative.
[US](con. 1940s) E. Thompson Tattoo (1977) 71: A feisty, round little ass.
[US]D. Woodrell Muscle for the Wing 24: A young gal [...] with [...] a feisty freckled face that dared you to make something of it.
[US]T. Dorsey Florida Roadkill 129: Suzanne Somers as the feisty-but-vulnerable love interest.
[UK]Guardian Guide 17–23 Mar. 98: An attempt [...] to magic up another feisty female underdog shaking up the system.