The last of this readily available drink (6)
I believe the answer is:
shandy
'drink' is the definition.
(shandy is a kind of drink)
'the last of this readily available' is the wordplay.
'the last of' indicates one should take the final letters.
'readily available' becomes 'handy' (I've seen this in another clue).
The last letter of 'this' is 's'.
's'+'handy'='SHANDY'
(Other definitions for shandy that I've seen before include "Beer/lemonade mixture" , "Beer/lemonade drink" , "Alcohol" , "Light beer" , "Beer and lemonade mix" .)