Business meeting might disintegrate rapidly (5,9)
I believe the answer is:
power breakfast
'business meeting' is the definition.
'power breakfast' can be an answer for 'meeting' (I have seen 'Early meeting' mean 'power breakfast' so perhaps 'meeting' could also mean 'power breakfast'). I am not certain of the 'business' bit.
'might disintegrate rapidly' is the wordplay.
'might' becomes 'power' (being mighty).
'disintegrate' becomes 'break' (I can't justify this - if you can you should believe this answer much more).
'rapidly' becomes 'fast' (synonyms).
'power'+'break'+'fast'='POWER BREAKFAST'
Can you help me to learn more?
(Other definitions for power breakfast that I've seen before include "Influence, by chance, quick early business meeting" , "summit early?" .)