Everybody catching salmon in the drink? (7)
I believe the answer is:
alcohol
'the drink?' is the definition.
(alcohol is a kind of drink)
'everybody catching salmon' is the wordplay.
'everybody' becomes 'all' (I've seen this before).
'catching' means one lot of letters goes inside another.
'salmon' becomes 'coho' (type of salmon).
'all' placed around 'coho' is 'ALCOHOL'.
'in' acts as a link.
(Other definitions for alcohol that I've seen before include "John Barleycorn" , "Wine, perhaps" , "Booze" , "The bottle" , "I could get you pickled" .)