Island century or so ago banning travel (7)
I believe the answer is:
corsica
'island' is the definition.
(Corsica is an example)
'century or so ago banning travel' is the wordplay.
'century' becomes 'C' (common abbreviation).
'so' becomes 'sic' ('so' in Latin).
'banning' indicates named letters should be taken away.
'travel' becomes 'go' (synonyms).
'ago' with 'go' removed is 'a'.
'c'+'or'+'sic'+'a'='CORSICA'
(Other definitions for corsica that I've seen before include "Napoleon's birth island" , "French island in Med" , "Napoleon's island birthplace" , "Island of W Italy, capital Ajaccio" , "French Mediterranean island" .)