Applications, purposes (4)
I believe the answer is:
uses
I believe this clue is a double definition.
'applications' is the first definition.
(use can mean an application or purpose)
'purposes' is the second definition.
('use' can be a synonym of 'purpose')
(Other definitions for uses that I've seen before include "What an employer does" , "Exercises" , "Puts to a particular purpose" , "Customs" , "Sues (anag.)" .)