An agreement among European nations that won’t take off in Australia (3)
I believe the answer is:
emu
I believe this is a double definition.
'an agreement among european nations' is the first definition.
(European Monetary Union)
'that won't take off in australia' is the second definition.
(flightless bird of Australia)
(Other definitions for emu that I've seen before include "Native Australian bird" , "Flightless Aus. bird" , "Long-necked bird" , "Aussie bird" , "that doesn't get off the ground" .)