Stopping shortly to register (5,2)
I believe the answer is:
check in
'register' is the definition.
(I've seen this before)
'stopping shortly' is the wordplay.
'stopping' becomes 'checking' (checking is a kind of stopping).
'shortly' means to remove the last letter.
'checking' with its last letter taken away is 'CHECK-IN'.
'to' is the link.
(Other definitions for check in that I've seen before include "Register on arrival like plane passenger" , "Report your presence at the airport" , "Registration desk" , "Reception area" , "procedure at airport" .)