Worrying about... (10)
I believe this is a double definition.
'worrying' is the first definition.
('concern' can be a synonym of 'worry')
'about' is the second definition.
(I've seen this before)
(Other definitions for concerning that I've seen before include "Worrying; about" , "anxiety" .)
(Other definitions for fearing that I've seen before include "Nervous" , "Dreading" , "Worried about" .)