Two points say for a shot (5)
I believe the answer is:
'shot' is the definition.
(I know that essay is a type of shot)
'two points say' is the wordplay.
'two points' becomes 'es' (two compass points).
'for a' is the link.
(Other definitions for essay that I've seen before include "Try - composition" , "example of Hazlitt's work" , "School compeosition" , "Thesis" , "Written academic work" .)