High-level meeting might end swiftly (5,9)
I believe the answer is:
'high-level 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'm unsure of the 'high-level' bit.
'might end swiftly' is the wordplay.
'might' becomes 'power' (being mighty).
'end' becomes 'break' (breaking is a kind of ending).
'swiftly' becomes 'fast' (synonyms).
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?" .)