Comparative form of feisty: more feisty(adjective)
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Use "feistier" in a sentence
"Karen Miller, founder of the Huntington Breast Cancer Action Coalition, says she believes the next generation is going to be "feistier" in demanding a cure for breast cancer."
"Canadians 'feistier' and ready to battle world: Poll"
"Prince Harry—William's younger brother, out of Eton Colllege— is the feistier one like Peyton."