Port and rhubarb trade reshaped capital of Malta (9)
I believe the answer is:
rotterdam
'port' is the definition.
(I've seen this before)
'rhubarb trade reshaped capital of malta' is the wordplay.
'rhubarb' becomes 'rot' (both can mean nonsense or false information).
'reshaped' indicates an anagram.
'capital of' indicates taking the first letters.
The initial letter of 'malta' is 'm'.
'trade' anagrammed gives 'terda'.
'rot'+'terda'+'m'='ROTTERDAM'
'and' is the link.
(Other definitions for rotterdam that I've seen before include "foreign city" , "European port" , "Dutch city and port" , "Major North Sea port - tarred tom (anag)" , "Netherlands port" .)