Tackle a gutted plump fish (8)
I believe the answer is:
approach
'tackle' is the definition.
(thesaurus)
'a gutted plump fish' is the wordplay.
'gutted' means to remove the middle letters (to gut something is to remove its insides).
'fish' becomes 'roach' (roach is a kind of fish).
'plump' with its centre removed is 'pp'.
'a'+'pp'+'roach'='APPROACH'
(Other definitions for approach that I've seen before include "Border on" , "Get closer to" , "initial proposal" , "Avenue" , "What happens before landing" .)