feist·y 
(fīstē)
(fīstē)adj. feist·i·er, feist·i·est
1. Full of spirit or determination; plucky or spunky: "Feisty, smart, and courageous child protagonists ... populate [her] fictional world" (Carolyn L. Shute). See Note at andiron.
2. Quarrelsome or aggressive: "A bunch of guys got tipsy ... One of them got feisty and starting swinging punches at the others" (Didi Emmons).
[From FEIST.]
feisti·ness n.