Definition of "plucky"

For my military knowledge, though I'm plucky and adventury, / Has only been brought down to the beginning of the century

1890, W. S. Gilbert, “The Modern Major-General”, in Songs of a Savoyard

"Dam' plucky of you, fixing it up like that. I kept that copper talking...give you a chance. By George, you did it perfectly."

1938, Norman Lindsay, Age of Consent, 1st Australian edition, Sydney, N.S.W.: Ure Smith, published 1962, page 231

At the start of the hearing, Mr. Bezos introduced himself as a lucky and humble example of the success of American democracy — the son of a plucky mother and a supportive, immigrant father who “fostered my curiosity and encouraged me to dream big.”

2020 July 29, “Lawmakers From Both Sides Take Aim at Big Tech Executives”, in New York Times‎