Issue makes one meditate moodily (5)
I believe the answer is:
brood
I believe this is a double definition.
'issue' is the first definition.
(thesaurus)
'one meditate moodily' is the second definition.
(I've seen this before)
'makes' acts as a link.
(Other definitions for brood that I've seen before include "Ponder mournfully" , "Clutch" , "Sulk; incubate" , "Think resentfully about family of children?" , "Family of young birds" .)