Good queen eating fish as well (7)
I believe the answer is:
besides
'as well' is the definition.
(thesaurus)
'good queen eating fish' is the wordplay.
'good queen' becomes 'bess' (Good Queen Bess was a nickname of Elizabeth I).
'eating' is an insertion indicator.
'fish' becomes 'ide' (I've seen this before).
'bess' enclosing 'ide' is 'BESIDES'.
(Other definitions for besides that I've seen before include "to boot" , "What's more" , "See bids (anag)" , "Additionally" , "In addition, as well" .)