Man owning power plant (5)
I believe the answer is:
maple
'plant' is the definition.
The answer is an example.
'man owning power' is the wordplay.
'man' becomes 'male' ().
'owning' is an insertion indicator.
'power' becomes 'p'.
'male' placed around 'p' is 'MAPLE'.
(Other definitions for maple that I've seen before include "Its leaf is the emblem of 8 down" , "Ample sort of tree" , "Its leaf is the emblem of Canada" , "Tree with syrupy sap" , "Tree with winged fruits" .)