Oddly silent recruit (6)
I believe the answer is:
enlist
'recruit' is the definition.
(enlisting is a kind of recruiting)
'oddly silent' is the wordplay.
'oddly' indicates anagramming the letters.
'silent' is an anagram of 'ENLIST'.
(Other definitions for enlist that I've seen before include "Take the Queen's shilling" , "Enrol in the services" , "Join the military" , "Enrol - recruit" , "Join up, sign on" .)