Dastardly
ahd-5
adjective.
Cowardly and malicious; base.
The Century Dictionary and Cyclopedia
Characterized by gross cowardice; meanly timid; base; sneaking.
the GNU version of the Collaborative International Dictionary of English
adjective.
Meanly timid; cowardly; base.
Wiktionary, Creative Commons Attribution/Share-Alike License
adjective.
in the manner of a
dastard
; marked by
cowardice
;
pusillanimous
adjective.
treacherous
; given to backstabbing
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
despicably cowardly