Bottle-opener always needed for drink (4)
I believe the answer is:
beer
'drink' is the definition.
(beer is a kind of drink)
'bottle-opener always needed' is the wordplay.
'opener' says to take the initial letters.
'always' becomes 'eer' (poetic way of saying ever).
'needed' says to put letters next to each other.
The first letter of 'bottle' is 'b'.
'b'+'eer'='BEER'
'for' is the link.
(Other definitions for beer that I've seen before include "Drink flavoured with hops" , "pint" , "See 4 down" , "eg Bitter" , "Brewery product" .)