The term 'EASTERN Chieftan' can be broken down into two words: 'EASTERN' and 'Chieftan'. The word 'EASTERN' refers to the geographical region of the world located east of Europe, including countries such as India, China, and Japan. The word 'Chieftan' is a title given to a leader of a tribe or clan, usually in a tribal society. The crossword solution for this term is 'EMIR', which is an Arabic title of nobility, similar to a prince or king. It is typically used to refer to the ruler of a city or state.