Oration slammed in Canadian province (7)
I believe the answer is:
ontario
'canadian province' is the definition.
(Ontario is an example)
'oration slammed' is the wordplay.
'slammed' indicates an anagram.
'oration' with letters rearranged gives 'ONTARIO'.
'in' acts as a link.
(Other definitions for ontario that I've seen before include "Province of central Canada" , "vast lake" , "A North American lake" , "Most populous Canadian province" , "Oration in Canadian province" .)