Old coin found by soldier round base (7)
I believe the answer is:
ignoble
'base' is the definition.
(both can mean dishonourable or shameful)
'old coin found by soldier round' is the wordplay.
'old coin' becomes 'noble' (I've seen this before).
'found by' is a charade indicator (letters next to each other).
'soldier' becomes 'GI' (GI can mean a US soldier).
'round' is a reversal indicator.
'gi' backwards is 'ig'.
'noble' put after 'ig' is 'IGNOBLE'.
(Other definitions for ignoble that I've seen before include "'Far from the madding crowd's . . . . . . . strife'" , "Unworthy" , "Base - in globe (anag)" , "I belong to base sort" , "Completely lacking in character or purpose" .)