Sick setter, pissed on rum, died (10)
I believe the answer is:
indisposed
'sick' is the definition.
('indisposed' can be similar in meaning to 'sick')
'setter pissed on rum died' is the wordplay.
'setter' becomes 'i' (the person that set the crossword).
'rum' indicates an anagram (rum can mean strange or unusual).
'died' becomes 'd'.
'pissed'+'on'='pissedon'
'pissedon' with letters rearranged gives 'ndispose'.
'i'+'ndispose'+'d'='INDISPOSED'
(Other definitions for indisposed that I've seen before include "Slightly unwell" , "Out of sorts" , "Poorly" .)