Bird leaflet containing concealed problem (10)
I believe the answer is:
flycatcher
'bird' is the definition.
(flycatcher is a kind of bird)
'leaflet containing concealed problem' is the wordplay.
'leaflet' becomes 'flyer' (I have seen 'Promotional leaflet' mean 'flyer' so perhaps 'leaflet' could also mean 'flyer').
'containing' is an insertion indicator.
'concealed problem' becomes 'catch' (I have seen 'Hidden problem' mean 'catch' so perhaps 'problem' could also mean 'catch'. I am not sure about the 'concealed' bit.).
'flyer' placed around 'catch' is 'FLYCATCHER'.
Can you help me to learn more?
(Other definitions for flycatcher that I've seen before include "Bird" , "one that may be spotted singing" , "airborne killer" , "sticky leg trap" .)