Rebuke salesperson given fish (8)
I believe the answer is:
reproach
'rebuke' is the definition.
(reproach is a kind of rebuke)
'salesperson given fish' is the wordplay.
'salesperson' becomes 'rep' (I've seen this before).
'given' says to put letters next to each other.
'fish' becomes 'roach' (roach is a kind of fish**).
'rep'+'roach'='REPROACH'
(Other definitions for reproach that I've seen before include "Blame, scold" , "Scold(ing)" , "Reprove gently" , "Take to task" , "Rebuke or expression of disappointment" .)