Try to equal bird, delayed (7)
I believe the answer is:
emulate
'try to equal' is the definition.
(I've seen this in another clue)
'bird delayed' is the wordplay.
'bird' becomes 'emu' (emu is a type of bird).
'delayed' becomes 'late' (running late).
'emu'+'late'='EMULATE'
(Other definitions for emulate that I've seen before include "Try to do as well as, copy" , "reproduce" , "Copy -- reach equality with" , "Model oneself on" , "ambitious veteran" .)