Clement holds girl in converted van (6,4)
I believe the answer is:
firing line
'van' is the definition.
(I've seen this before)
'clement holds girl in converted' is the wordplay.
'clement' becomes 'fine' (similar in meaning).
'holds' means one lot of letters goes inside another.
'converted' indicates an anagram.
'girl'+'in'='girlin'
'girlin' is an anagram of 'iringl'.
'fine' enclosing 'iringl' is 'FIRING LINE'.
(Other definitions for firing line that I've seen before include "Position of exposure to criticism" , "van" , "troops at the front" , "where criticism is inevitable" .)