Unexpectedly interrupt meal half-heartedly, even absurdly (9)
I believe the answer is:
supervene
'unexpectedly interrupt meal' is the definition.
I can't judge whether this defines the answer.
'half-heartedly even absurdly' is the wordplay.
'half-heartedly' becomes 'super' (I am not sure about this - if you are sure you should believe this answer much more).
'absurdly' indicates anagramming the letters.
'even' with letters rearranged gives 'vene'.
'super'+'vene'='SUPERVENE'
Can you help me to learn more?
(Another definition for supervene that I've seen is " Occur as a change, interruption or addition to the status quo".)