Anarchy in port the conclusion of Brexit? (4)
I believe the answer is:
riot
'anarchy' is the definition.
(I've seen this in another clue)
'port the conclusion of brexit?' is the wordplay.
'port' becomes 'rio' (Rio de Janeiro is a port).
'the conclusion of' says to take the final letters.
The last letter of 'brexit' is 't'.
'rio'+'t'='RIOT'
'in' acts as a link.
(Other definitions for riot that I've seen before include "Crowd violence" , "Uprising" , "Wild disturbance by crowd of people" , "Take to the streets" , "Civil unrest" .)