A number take a bird to be cowardly (6)
I believe the answer is:
craven
'be cowardly' is the definition.
(synonyms)
'a number take a bird' is the wordplay.
'a number take' becomes 'c' (I can't justify this - if you can you should believe this answer much more).
'a bird' becomes 'raven' (raven is a kind of bird).
'c'+'raven'='CRAVEN'
'to' is the link.
Can you help me to learn more?
(Other definitions for craven that I've seen before include "Cowardly - Yorkshire area" , "Cowardly, abjectly afraid" , "Lacking courage, cowardly" , "Without backbone" , "Cowardly, spineless" .)