Send home agent at speed -- one in hiding (10)
I believe the answer is:
repatriate
'send home' is the definition.
(I've seen this before)
'agent at speed one in hiding' is the wordplay.
'agent' becomes 'rep' (short for representative).
'speed' becomes 'rate' (the speed at which something happens).
'one' becomes 'i' (Roman numeral).
'in hiding' indicates putting letters inside (some letters hide inside others).
'rate' going around 'i' is 'riate'.
'rep'+'at'+'riate'='REPATRIATE'
(Other definitions for repatriate that I've seen before include "Send home" , "bring home" , "Send (someone) back to their own country" , "Rescue traveller" .)