Flightless bird originally eliciting letter from abroad (3)
I believe the answer is:
emu
'flightless bird' is the definition.
(emu is a kind of flightless bird)
'originally eliciting letter from abroad' is the wordplay.
'originally' suggests taking the first letters.
'letter from abroad' becomes 'mu' (Greek letter).
The initial letter of 'eliciting' is 'e'.
'e'+'mu'='EMU'
(Other definitions for emu that I've seen before include "it can't get off the ground" , "one offering challenge to Hull?" , "Australian bird related to the ostrich" , "Aussie runner" , "Parky's nemesis" .)