Leg of mutton American soldier acquired (5)
I believe the answer is:
gigot
'leg of mutton' is the definition.
(I've seen this before)
'american soldier acquired' is the wordplay.
'american soldier' becomes 'gi'.
'acquired' becomes 'got' ('get' can be a synonym of 'acquire').
'gi'+'got'='GIGOT'
(Other definitions for gigot that I've seen before include "A bit of mutton" , "joint of meat" , "Perceive by touch" , "Mutton or lamb leg" .)