College inventor making contribution to security (4)
I believe the answer is:
yale
I believe this is a double definition.
'college' is the first definition.
'inventor making contribution to security' is the second definition.
(Linus Yale Jr, lock inventor)
(Other definitions for yale that I've seen before include "Very important university" , "University in USA" , "US university; lock" , "American university or kind of lock" , "Mass. university" .)