Infamous head of occupied port seized by other people? (9)
I believe the answer is:
'infamous' is the definition.
'head of occupied port seized by other people?' is the wordplay.
'head of' suggests taking the first letters.
'port' becomes 'rio' (Rio de Janeiro is a port).
'seized by' means one lot of letters goes inside another.
'other people?' becomes 'not us'.
The initial letter of 'occupied' is 'o'.
'orio' put within 'notus' is 'NOTORIOUS'.
(Other definitions for notorious that I've seen before include "having a terrible reputation?", "Hitchcock film", "Having a bad name", "Infamous", "worthy of shame?".)