Recruit is strangely silent (6)
I believe the answer is:
enlist
'recruit' is the definition.
(I know that enlist is a type of recruit)
'strangely silent' is the wordplay.
'strangely' indicates an anagram.
'silent' with letters rearranged gives 'ENLIST'.
'is' is the link.
(Other definitions for enlist that I've seen before include "Register" , "Listen (anag.)" , "Sign on -- 13 (anag)" , "Join up, sign on" , "Join up in silent way" .)