Traffic controllers study directions (5)
I believe the answer is:
'traffic controllers' is the definition.
(I've seen this in another clue)
'study directions' is the wordplay.
'study' becomes 'con' (con can mean to study).
'directions' becomes 'es' (east and south - two directions).
(Other definitions for cones that I've seen before include "Cornets" , "Round shapes with tapering sides" , "Shapes of wafers for ice-cream" , "(Volcano) peaks" , "subject of a former hotline" .)