Try rum to have fun and finally become happy (4-8)
I believe the answer is:
good-humoured
'try rum' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'fun and finally become happy' is the wordplay.
I cannot really see how this works, but
'become' could be 'go' (synonyms) and 'go' is located in the answer.
This explanation may well be incorrect...
'to have' is the link.
Can you help me to learn more?
(Another definition for good-humoured that I've seen is " Genial, cheerful".)