Hard/soft - no mixture, et cetera (3,2,5)
I believe the answer is:
and so forth
'et cetera' is the definition.
(I've seen this in another clue)
'hardsoft no mixture' is the wordplay.
'mixture' indicates an anagram.
'hardsoft'+'no'='hardsoftno'
'hardsoftno' with letters rearranged gives 'AND SO FORTH'.
(Other definitions for and so forth that I've seen before include "etc." , "imagine what follows" , "implies others of the same type" , "Et cetera" , "Along with other things" .)