Complaint of diner having, say, sipped rum (9)
I believe the answer is:
dyspepsia
'complaint of diner' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'say sipped rum' is the wordplay.
'rum' indicates an anagram (rum can mean strange or unusual).
'say'+'sipped'='saysipped'
'saysipped' is an anagram of 'DYSPEPSIA'.
'having' is the link.
Can you help me to learn more?
(Other definitions for dyspepsia that I've seen before include "digestive complaint" , "stomach complaint" , "Stomach upset - spied a spy (anag)" , "It was enough to make any man sick" , "Heartburn" .)