craven
ˈkreɪv(ə)n
adjective
contemptibly lacking in courage; cowardly.
a craven abdication of his moral duty
cowardly,lily-livered,faint-hearted,chicken-hearted,pigeon-hearted,spiritless,spineless,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
noun
a cowardly person.