Army officer with 50 yen on average (9)
I believe the answer is:
generally
'average' is the definition.
(thesaurus)
'army officer with 50 yen' is the wordplay.
'army officer' becomes 'general' (type of army officer).
'with' is a charade indicator (letters next to each other).
'50' becomes 'l' (Roman numeral).
'yen' becomes 'y'.
'general'+'l'+'y'='GENERALLY'
'on' acts as a link.
(Other definitions for generally that I've seen before include "as usual" , "In most cases, as a general rule" , "For the most part" , "In most cases, usually" , "Usually, as a rule" .)