Off to obtain one's hot rum (10)
I believe the answer is:
outlandish
'rum' is the definition.
(thesaurus)
'off to obtain one's hot' is the wordplay.
'off' becomes 'out' (**).
'to obtain' becomes 'land'.
'one's' becomes 'is' (Roman numeral).
'hot' becomes 'h'.
'out'+'land'+'is'+'h'='OUTLANDISH'
(Other definitions for outlandish that I've seen before include "Bizarre - hound's tail (anag)" , "Lad shoutin' (anag)" , "Exotic" .)