Cub or colt (6)
I believe the answer is:
rookie
This clue is a double definition.
'cub' is the first definition.
(I know that cub can be written as rookie)
'colt' is the second definition.
(thesaurus)
(Other definitions for rookie that I've seen before include "inexperienced fighter" , "untested type" , "Army or police recruit" , "untrained soldier" , "Raw recruit" .)