Eat too much, so dreaming is awful (10)
I believe the answer is:
gormandise
'eat too much' is the definition.
(to gormandise is to eat good food to excess)
'so dreaming is awful' is the wordplay.
'is awful' indicates an anagram.
'so'+'dreaming'='sodreaming'
'sodreaming' with letters rearranged gives 'GORMANDISE'.
(Other definitions for gormandise that I've seen before include "gorge" , "scoff like a 28 [PIG] ?" .)