Primarily a lovable eccentric (5,3)
I believe the answer is:
above all
'primarily' is the definition.
(above all can mean primarily or especially)
'a lovable eccentric' is the wordplay.
'eccentric' indicates an anagram.
'lovable' with letters rearranged gives 'boveall'.
'a'+'boveall'='ABOVE ALL'
(Other definitions for above all that I've seen before include "Mainly" , "What 18 [EVEREST] is" , "at the end of the day?" , "Especially" , "Most importantly" .)