Pusillanimous

Definition of pusillanimous
: lacking courage and resolution : marked by contemptible timidity

Synonyms
chicken, chicken-livered, chickenhearted, cowardly, craven, dastardly, gutless, lily-livered, milk-livered [archaic], poltroon, recreant, spineless, unheroic, yellow

Antonyms
brave, courageous, daring, dauntless, doughty, fearless, gallant, greathearted, gutsy, hardy, heroic (also heroical), intrepid, lionhearted, stalwart, stout, stouthearted, valiant, valorous