Register at society (5)
I believe the answer is:
lodge
This clue is a double definition.
'register' is the first definition.
(I've seen this before)
'society' is the second definition.
(I know that society can be written as lodge)
'at' is the link.
(Other definitions for lodge that I've seen before include "Small house at gates of park or estate" , "next door to Mansion House?" , "Comic novelist" , "Small dwelling, part of estate" , "Gatehouse - deposit" .)