One nationalist has acquired some bullion? (5)
I believe the answer is:
ingot
'some bullion?' is the definition.
(bullion is a kind of ingot)
'one nationalist has acquired' is the wordplay.
'one' becomes 'i' (Roman numeral).
'nationalist' becomes 'n' (abbreviation in politics).
'has' is a charade indicator (letters next to each other).
'acquired' becomes 'got' ('get' can be a synonym of 'acquire').
'i'+'n'+'got'='INGOT'
(Other definitions for ingot that I've seen before include "Lump of gold etc" , "Block of precious metal" , "Metallic bar" , "Mass of precious metal" , "Moulded metal bar" .)