Secures site badly (4)
I believe the answer is:
ties
'secures' is the definition.
(tying is a kind of securing)
'site badly' is the wordplay.
'badly' indicates anagramming the letters (letters in the wrong order).
'site' with letters rearranged gives 'TIES'.
(Other definitions for ties that I've seen before include "Items of neckwear" , "obligations" , "Binds with male neckwear" , "Connects" , "Links" .)