Strive to equal bird that's not on time (7)
I believe the answer is:
emulate
'strive to equal' is the definition.
(I've seen this in another clue)
'bird that's not on time' is the wordplay.
'bird' becomes 'emu' (emu is a type of bird).
'that's not on time' becomes 'late' (I've seen this before).
'emu'+'late'='EMULATE'
(Other definitions for emulate that I've seen before include "Try to equal (object of admiration)" , "Follow in the footsteps of" , "Copy - rival" , "Imitate - rival" , "Follow suit" .)