Pay corps to recruit a foreign judge (10)
I believe the answer is:
remunerate
'pay' is the definition.
(I know that remunerate is a type of pay)
'corps to recruit a foreign judge' is the wordplay.
'corps' becomes 'reme' (Royal Electrical and Mechanical Engineers).
'to recruit' means one lot of letters goes inside another (in the sense of bringing in).
'a foreign' becomes 'un' ('a' translated into French).
'judge' becomes 'rate' (rating is a kind of judging).
'reme' enclosing 'un' is 'remune'.
'remune'+'rate'='REMUNERATE'
(Other definitions for remunerate that I've seen before include "Make payment to" , "reward" , "Pay (for work done)" , "Pay for service" .)