Drink needed after Foreign Office meeting (5)
I believe the answer is:
forum
'meeting' is the definition.
(forum is a kind of meeting)
'drink needed after foreign office' is the wordplay.
'drink' becomes 'rum' (I've seen this before).
'needed after' says to put letters next to each other.
'foreign office' becomes 'fo'.
'rum' after 'fo' is 'FORUM'.
(Other definitions for forum that I've seen before include "Tribunal" , "place for debate" , "Place of assembly for the people in ancient Greece" , "Meeting for debate" , "historically square" .)