Imagine a personality (6)
I believe the answer is:
figure
I believe this clue is a double definition.
'imagine' is the first definition.
(figuring is a kind of imagining)
'a personality' is the second definition.
(thesaurus)
(Other definitions for figure that I've seen before include "Reckon" , "Work out" , "Symbol representing a number" , "Diagram or digit" , "Number; statue" .)