Unlimited load of French ship entering Black Sea Port (6)
I believe the answer is:
odessa
'black sea port' is the definition.
(Ukrainian port on the Black Sea)
'unlimited load of french ship entering' is the wordplay.
'unlimited' means to look at the middle letters (remove the limits/outer letters).
'of french' becomes 'de' ('of' in French).
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'entering' is an insertion indicator.
The middle letters of 'load' are 'oa'.
'de'+'ss'='dess'
'oa' placed around 'dess' is 'ODESSA'.
(Other definitions for odessa that I've seen before include "Port city of Ukraine" , "Seaport" , "Do seas come into Ukrainian city?" , "Black Sea location" , "Ukrainian location" .)