At the weekend a chair is put out for port (7)
I believe the answer is:
karachi
'port' is the definition.
(I have seen 'Pakistani port ' mean 'karachi' so perhaps 'port' could also mean 'karachi')
'at the weekend a chair is put out' is the wordplay.
'at' is a charade indicator (letters next to each other).
'the weekend' becomes 'k' (I've seen this in other clues).
'is put out' indicates an anagram.
'chair' is an anagram of 'rachi'.
'k' next to 'a' is 'ka'.
'ka'+'rachi'='KARACHI'
'for' acts as a link.
(Other definitions for karachi that I've seen before include "Pakistan port, once capital" , "Pakistani port" , "Pakistani seaport and former capital" , "Major city of Pakistan" , "Pakistani city" .)