I. -dlē, -li adverb
Etymology: Middle English, from coward (II) + -ly
: in a cowardly manner
II. adjective
Etymology: coward (I) + -ly
: like or befitting a coward : showing a coward's nature : marked by or arising from utter lack of courage : ignobly timid and faint-hearted
cowardly dogs, ye will not aid me then — P.B.Shelley
if you want to make charges, make them openly. I will not listen to cowardly hints — Sinclair Lewis
Synonyms:
coward , pusillanimous , poltroon , craven , dastardly , recreant : cowardly , the most general term of this group, and coward indicate weak and ignoble timidity
a timid and cowardly man, who, according to one account, now surrendered Lothian to King Malcolm for fear that he might avenge the victories won over him by his brother — E.A.Freeman
you are an incompetent cowardly rascal, sir! damn me if you're not! are you afraid of a crowd of bloody savages whilst you have arms in your hands — C.B.Nordhoff & J.M.Hall
you laughed in my face as you are trying to laugh now, only your coward heart cannot keep your lips from twitching — A. Conan Doyle
pusillanimous connotes abjectness and contemptibility
I lived in a continual indefinite pining fear; tremulous, pusillanimous, apprehensive of I knew not what — Thomas Carlyle
poltroon , uncommon as an adjective, suggests complete cowardice
we had to make a show of impotence, which gave them to understand that the Arabs were too poltroon to cut the line near Maan and keep it cut — T.E.Lawrence
craven implies extreme defeatism and complete lack of resistance
your prayers will do more for me … than the swords of the craven sycophants would have done had they remained true — Alfred Tennyson
a man whom a craven fear had made insensible to shame — T.B.Macaulay
dastardly is used in references to situations and personalities blending utter cowardice with the treacherous or outrageous
since the unprovoked and dastardly attack by Japan on Sunday, December 7th — F.D.Roosevelt
they'll spare the women; but my man tells me they have taken an oath to give no quarter to the men — the dastardly cowards — W.M.Thackeray
recreant , currently more common in the meaning of apostate, implies abject lack of resistance
when I was bewildered and recreant and was inclined to go back upon all my fiercest convictions — Victoria Sackville-West