adjective

lacking courage.

he was a weak, cowardly man

faint-hearted,lily-livered,chicken-hearted,pigeon-hearted,spiritless,spineless,craven,timid,timorous,fearful,trembling,quaking,shrinking,cowering,afraid of one’s own shadow,pusillanimous,weak,feeble,soft,yellow,chicken,weak-kneed,gutless,yellow-bellied,wimpish,wimpy,sissy,sissified,wet,candy-assed,poltroon,recreant,poor-spirited,chickenshit

adverb

in a way which shows a lack of courage.