Tax incorporating right to fish (5)
I believe the answer is:
troll
'fish' is the definition.
(thesaurus)
'tax incorporating right' is the wordplay.
'tax' becomes 'toll' (I've seen this in other clues).
'incorporating' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'toll' enclosing 'r' is 'TROLL'.
'to' is the link.
(Other definitions for troll that I've seen before include "Possibly a monster" , "cyber-bully" , "Ugly Norse dwarf" , "Dwarfish creature" , "unwanted contributor to site?" .)