Worker coming to one cold region or another (9)
I believe the answer is:
antarctic
'another' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'worker coming to one cold region' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'coming to' means one lot of letters go next to another.
'one cold region' becomes 'arctic' (the Arctic is a cold region).
'ant'+'arctic'='ANTARCTIC'
'or' acts as a link.
(Other definitions for antarctic that I've seen before include "Penguin's home" , "Region around the south pole" , "Area around the South Pole" , "Of South Polar regions" , "Of far southern regions" .)