Military medal worn under Australian's coat, etc. (3,2,2)
I believe the answer is:
and so on
'etc' is the definition.
(I've seen this before)
'military medal worn under australian's coat' is the wordplay.
'military medal' becomes 'DSO' (distinguished service order).
'worn' becomes 'on' (as in clothes having clothes on).
'under' is a charade indicator (letters next to each other) (below, in a down clue).
'coat' says to hollow out the word (remove centre letters) (only the letters which coat the word are used).
'australian' with its middle removed is 'an'.
'dso'+'on'='dsoon'
'dsoon' after 'an' is 'AND SO ON'.
(Other definitions for and so on that I've seen before include "Et cetera" , "Etc - in English and in full" , "Continuing in the same way" , "I say no more" , "Etc. (3.2.2)" .)