dastardly
Sneakily cruel behavior
Dastardly describes acts that are sneaky, underhanded, and cowardly—villainy without honor.
A dastardly deed is treacherous rather than brave: a dastardly plot to poison the king.
The word has an old-fashioned, melodramatic ring, often evoking cartoon villains twirling mustaches: What dastardly scheme are you hatching now?
Extremely wicked or criminal
- nefariousExtremely evil or villainous
- evilProfound moral wickedness
- wickedEvil or slang-excellent
- diabolicalExtremely wicked or cruel
fiendish · malevolent · heinous · vile · monstrous · cruel · malicious · sinister
Disloyal and dangerous
- betrayalBreaking of trust
- backstabbingCovert betrayal of trust
- perfidiousDeliberately breaking faith
- traitorousGuilty of betrayal
deceitful · duplicitous · disloyal · double-dealing · two-faced · underhanded · untrustworthy · false
Devising a secret plan
- connivingSecretly planning wrongdoing
- cunningSly, scheming cleverness
- deviousUnderhanded and calculating
- calculatingColdly self-serving in strategy
manipulative · conspiracy · intrigue · machination · subterfuge · stratagem · ploy · ruse
villainous
Extremely wicked or criminal
diabolical · fiendish · malevolent · heinous · vile · monstrous · cruel · malicious · sinister · despicable
treacherous
Disloyal and dangerous
- betrayalBreaking of trust
- backstabbingCovert betrayal of trust
- perfidiousDeliberately breaking faith
traitorous · deceitful · duplicitous · disloyal · double-dealing · two-faced · underhanded · untrustworthy · false · recreant
plotting
Devising a secret plan
- connivingSecretly planning wrongdoing
- cunningSly, scheming cleverness
- deviousUnderhanded and calculating
calculating · manipulative · conspiracy · intrigue · machination · subterfuge · stratagem · ploy · ruse · artifice
dastardlynoble
Titled or virtuous
honorable · virtuous · gallant · chivalrous · upstanding