The term 'TALL BIRD' can be represented by three different crossword solutions: EMU (3 letters), RHEA (4 letters), and EMEU (4 letters). The EMU is a large, flightless bird native to Australia. It is the second-largest living bird by height, after the ostrich. The RHEA is a large, flightless bird native to South America. It is the largest bird in the Americas and is closely related to the EMU. The emeu is a large, flightless bird native to New Caledonia. It is the third-largest living bird by height, after the ostrich and the EMU.