A tear to fall (4)
I believe the answer is:
drop
I believe this is a double definition.
'a tear' is the first definition.
(thesaurus)
'fall' is the second definition.
('drop' can be a synonym of 'fall')
'to' is the link.
(Other definitions for drop that I've seen before include "small amount of alcohol" , "See 1" , "Tiny bit of liquid" , "Collapse, globule" , "sack" .)