Cooler, retired agricultural worker? (9)
I believe the answer is:
extractor
'cooler' is the definition.
(as in an extractor fan, something that cools)
'retired agricultural worker?' is the wordplay.
'retired' becomes 'ex' (prefix meaning former or onetime).
'agricultural worker?' becomes 'tractor' (vehicle used for agriculture).
'ex'+'tractor'='EXTRACTOR'
(Other definitions for extractor that I've seen before include "Device for removing air from a space" , "Sort of fan" , "Remover" , "Variety of fan" , "Eg, kitchen fan" .)