"The Audacity of Hope” author (5)
I believe the answer is:
obama
'the audacity of hope author' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for obama that I've seen before include "Leading man" , "Politician" , "President awarded the 2009 Nobel Peace Prize" , "Important figure" , "US president born in Hawaii" .)