Synonyms of dastardly in English:

dastardly


See US English definition of dastardly

See UK English definition of dastardly

See Spanish definition of ruin

adjective

1‘a dastardly plan was hatched to kidnap him’

SYNONYMS
wicked, evil, iniquitous, heinous, villainous, diabolical, diabolic, fiendish, vicious, murderous, barbarous, cruel, black, dark, rotten, nefarious, vile, foul, monstrous, shocking, outrageous, atrocious, abominable, reprehensible, despicable, execrable, corrupt, degenerate, reprobate, sordid, depraved, dissolute, bad, base, mean, low, dishonourable, dishonest, unscrupulous, unprincipled, underhand, roguish
informal crooked, low-down, stinking, dirty, shady, rascally, scoundrelly
British informal beastly, not cricket
Law malfeasant
rare egregious, flagitious
ANTONYMS

noble, praiseworthy