Dastard
Part of speech: noun
Definition: A malicious coward.
Part of speech: adjective
Definition: meanly shrinking from danger, cowardly, dastardly
Cowardly
Part of speech: adverb
Definition: In the manner of a coward.
Part of speech: adjective
Definition: Showing cowardice. Lacking in courage, unacceptably fearful, usually meant with some implication of a lack of consideration for others.
Example sentence: The people to fear are not those who disagree with you, but those who disagree with you and are too cowardly to let you know.