Grasping editor carried by horse (6)
I believe the answer is:
greedy
'grasping' is the definition.
(I know that grasping can be written as greedy)
'editor carried by horse' is the wordplay.
'editor' becomes 'ed' (abbreviation).
'carried by' indicates putting letters inside.
'horse' becomes 'grey' (I've seen this before).
'ed' placed within 'grey' is 'GREEDY'.
(Other definitions for greedy that I've seen before include "Keen" , "Wanting too much" , "Gluttonous" , "Over-desirous of food" , "Grasping" .)