Entertain a source of inspiration (5)
I believe the answer is:
amuse
'entertain' is the definition.
(amuse can mean to entertain or divert)
'a source of inspiration' is the wordplay.
'source of inspiration' becomes 'muse' (I've seen this before).
'a'+'muse'='AMUSE'
(Other definitions for amuse that I've seen before include "Delight" , "Divert or entertain mildly" , "interest" , "Make (someone) laugh" , "Keep someone entertained" .)