Flightless birds are birds that cannot fly due to the lack of certain physical adaptations. The crossword solutions for the term flightless bird include MOA (3 letters), CASSOWARY (9 letters), RHEA (4 letters), DODO (4 letters), KIWI (4 letters), EMU (3 letters), WEKA (4 letters), OSTRICH (7 letters), RATITE (6 letters), PENGUIN (7 letters), NOTORNIS (8 letters), TAKAHE (6 letters), SST (3 letters), and EMEU (4 letters). These birds are found in various parts of the world, from New Zealand to South America. They are characterized by their inability to fly, as well as their strong legs and feet which they use for running and swimming.