Answer: Using context clues, the word "craven" can be defined as "cowardly".
Explanation: The word "craven" is an adjective and it is used to describe a person that has lack of courage. In that way, "craven" can be defined as "cowardly", which is also an adjective. Moreover, there are context clues in the sentence. Context clues are words that function as hints and that help the reader to infer the meaning of an unknown word. In the case of "craven", the context clue is the phrase "a single brave thing".