Regularly behind peers: feel down about this? (5)
I believe the answer is:
eider
'feel down about this?' is the definition.
('down' refers to bird feathers eg an eider's)
'regularly behind peers' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'behind'+'peers'='behindpeers'
The alternating letters of 'behindpeers' are 'EIDER'.
(Other definitions for eider that I've seen before include "Quilt- furnishing duck" , "Duck noted for down" , "Type of duck" , "Sea-duck" , "Northern sea duck" .)