Port does badly when in recession (6)
I believe the answer is:
odessa
'port' is the definition.
(I've seen this before)
'does badly when in recession' is the wordplay.
'badly' is an anagram indicator.
'when' becomes 'as'.
'in recession' says the letters should be written backwards.
'as' reversed gives 'sa'.
'does' is an anagram of 'odes'.
'odes'+'sa'='ODESSA'
(Other definitions for odessa that I've seen before include "Battleship Potemkin mutiny port" , "Ukrainian naval base" , "Port city of Ukraine" , "Port city on the Black Sea" , "Ukrainian location" .)