Liveliness of Brazilian capital and port (4)
I believe the answer is:
brio
'liveliness' is the definition.
(thesaurus)
'brazilian capital and port' is the wordplay.
'capital' indicates taking the first letters.
'and' is a charade indicator (letters next to each other).
'port' becomes 'rio' (I've seen this before).
The first letter of 'brazilian' is 'b'.
'b'+'rio'='BRIO'
'of' is the link.
(Other definitions for brio that I've seen before include "In music, con ..... means with dash and verve" , "Dash or verve, from Italian" , "Animation (Italian)" , "Vivacity - spirit" , "Spiritedness" .)