Secure link (3-2)
This clue is a double definition.
'secure' is the first definition.
(I've seen this before)
'link' is the second definition.
(I've seen this before)
(Other definitions for tie-up that I've seen before include "Link, connection" , "affiliation" , "Bind" , "Tether" , "Link (between companies)" .)
This clue is a double definition.
'secure' is the first definition.
(tying is a kind of securing)
'link' is the second definition.
(synonyms)
(Other definitions for tie that I've seen before include "Draw - connection" , "Fixture" , "Accessory" , "Knot; link" , "Fasten; level game" .)