Pub in Pimlico — calm (5)
I believe the answer is:
local
'pub' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
(Other definitions for local that I've seen before include "bar" , "Anaesthetic that numbs one area of the body" , "Pub - of a particular area" , "Of the particular neighbourhood" , "Stopping regularly" .)