Port number six depressesd (4,3)

I believe the answer is:

novi sad

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'port' is the definition.
(I have seen 'European port' mean 'novi sad' so perhaps 'port' could also mean 'novi sad')

'number six depressesd' is the wordplay.
'number' becomes 'no' (abbreviation for 'number').
'six' becomes 'VI' (Roman numerals).
'depressesd' becomes 'sad' (I can't explain this - if you can you should believe this answer much more).
'no'+'vi'+'sad'='NOVI SAD'

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(Other definitions for novi sad that I've seen before include "Serbian city" , "Serbian town" , "European port" .)

I've seen this clue in The Daily Express.

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