Colder in Canada in every respect, originally (5)
I believe the answer is:
icier
'colder' is the definition.
('icy' can be similar in meaning to 'cold')
'in canada in every respect originally' is the wordplay.
'originally' indicates taking the first letters.
The first letters of 'in canada in every respect' is 'ICIER'.
(Other definitions for icier that I've seen before include "Colder even than 31 Across" , "More cold - really freezing" , "Even more frozen" , "More slippery" , "More chilly" .)