The crossword solution for the term 'HISTORY OPENING' is ETHNO, which is a five-letter word. ETHNO is derived from the Greek word ethnos, which means 'NATION' or 'PEOPLE'. It is used to refer to the study of different cultures and their customs, beliefs, and traditions. ETHNO is often used in the context of anthropology, sociology, and history, as it is concerned with the study of human societies and their development over time.