Like a magnate posing a question (6)
I believe the answer is:
asking
'posing a question' is the definition.
(I've seen this before)
'like a magnate' is the wordplay.
'like' becomes 'as'.
'a magnate' becomes 'king' ('king' can be a synonym of 'magnate').
'as'+'king'='ASKING'
(Other definitions for asking that I've seen before include "Presenting petition" , "Demanding" , "Directing a question" , "Direction a question" , "Begging" .)