US university rugby forward providing form of security (4,4)
I believe the answer is:
yale lock
'form of security' is the definition.
'us university rugby forward' is the wordplay.
'us university' becomes 'yale' (I've seen this before).
'rugby forward' becomes 'lock' (lock is an example).
'yale'+'lock'='YALE LOCK'
'providing' acts as a link.
(Other definitions for yale lock that I've seen before include "security" , "One may secure entrance" , "that restricts entry" , "piece with unique key" .)