Worried about the future? (5)
I believe the answer is:
tense
I believe this clue is a double definition.
'worried' is the first definition.
(thesaurus)
'the future?' is the second definition.
(future is a kind of tense)
'about' is the link.
(Other definitions for tense that I've seen before include "show strain" , "Anxious - future, perhaps?" , "in the past, perhaps" , "Anxious, nervous" , "under pressure" .)