It's fine in spring (4)
I believe the answer is:
well
I believe this is a double definition.
'it's fine' is the first definition.
('well' can be similar in meaning to 'fine')
'spring' is the second definition.
(thesaurus)
'in' is the link.
(Other definitions for well that I've seen before include "Lift-shaft" , "Sunken shaft; very much" , "all right" , "satisfactory manner?" , "Spring - in good condition" .)