The word “Vimana” originates from the Sanskrit words Vi-Mana, ‘Vi’ meaning ‘Bird’ and ‘Mana’ meaning ‘like’. The interpretation will be ‘like bird’. Owing to similarity with birds, it is named ‘vimana’. The word ‘andaja’ as related to birds means ‘egg-born’. The word vimana, though of purely ancient Indian origin, is widely adapted and used by not only writers on this science in India, but also extensively quoted as such by the researchers the world over. Basis of arriving at this definition is not strange. Researchers on flying machines from other parts of the world have also looked at flying birds as their origin of inspiration and conceptualization. Ancient Indian scientists were no different in their approach.