Catch journalist drinking rum? On the contrary (7)
I believe the answer is:
haddock
'catch' is the definition.
(haddock is a kind of fish)
'journalist drinking rum? on the contrary' is the wordplay.
'journalist' becomes 'hack' (I've seen this in other clues).
'drinking' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'rum?' becomes 'odd' (I've seen this before).
'on the contrary' is a reversal indicator (letters in the opposite or contrary direction).
'odd' in reverse letter order is 'ddo'.
'hack' placed around 'ddo' is 'HADDOCK'.
(Other definitions for haddock that I've seen before include "Fish, often smoked" , "White fish" , "ish" , "Swimmer" , "Fish like cod but smaller" .)