Mix with general public as royal personage? Get lost! (2,9)
I believe the answer is:
go walkabout
'get lost' is the definition.
'mix with general public as royal personage?' is the wordplay.
I cannot quite see how this works, but
'with' could be 'w' (abbreviation) and 'w' is found in the answer.
'public' could be 'out' (I've seen this before) and 'out' is present in the answer.
This may be the basis of clue (or it may be nonsense).
(Another definition for go walkabout that I've seen is " Leave a group for a while without telling anyone; journey into the (Australian) bush".)