Insufficiency, deficit (8)
I believe the answer is:
shortage
I believe this is a double definition.
'insufficiency' is the first definition.
(shortage is a kind of insufficiency)
'deficit' is the second definition.
(synonyms)
(Other definitions for shortage that I've seen before include "Need" , "Lack, deficiency" , "Dearth, lack" , "Insufficiency" , "Horse tag (anag.)" .)