Reserve squad (10)
I believe the answer is:
detachment
I believe this clue is a double definition.
'reserve' is the first definition.
(thesaurus)
'squad' is the second definition.
(I've seen this before)
(Other definitions for detachment that I've seen before include "Disengagement" , "Coolness - body of troops" , "reserve" , "Military unit" , "indifference" .)