'Dastardly' definitions:

Definition of 'dastardly'

(from WordNet)
adjective
Despicably cowardly; "the unprovoked and dastardly attack by Japan on...December 7th"- F.D. Roosevelt [syn: dastard(a), dastardly]

Definition of 'Dastardly'

From: GCIDE
  • Dastardly \Das"tard*ly\, a. Meanly timid; cowardly; base; as, a dastardly outrage. [1913 Webster]