Bird similar to an ostrich (3)
I believe the answer is:
emu
'bird similar to an ostrich' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for emu that I've seen before include "Aussie bird" , "Parky's nemesis" , "it can't get off the ground" , "Australian bird related to the ostrich" , "Long-necked bird" .)