Super fireplace, we hear (5)
I believe the answer is:
great
'super' is the definition.
'fireplace we hear' is the wordplay.
'fireplace' becomes 'grate' (I've seen this before).
'we hear' shows a homophone (sound like).
'grate' is a homophone of 'GREAT'.
(Other definitions for great that I've seen before include "The Plough" , "Wonderful" , "Very good or very big" , "and 12 Down: Powerful dog" , "Mum's dad's mum, for example" .)