Hear about emu relative (4)
I believe the answer is:
rhea
'emu relative' is the definition.
(I've seen this in another clue)
'hear about' is the wordplay.
'about' indicates anagramming the letters.
'hear' is an anagram of 'RHEA'.
(Other definitions for rhea that I've seen before include "Large flightless bird" , "Flightless bird -- satellite of Saturn" , "nonflyer" , "Fast-running flightless bird" , "Flightless bird - Greek fertility goddess" .)