James Rattray in the context of "Emir"

Emir (/əˈmɪər, eɪˈmɪər, ˈeɪmɪər/; Arabic: أمير ʾamīr [ʔæˈmiːr] (listen), also transliterated as amir, is a word of Arabic origin that can refer to a male monarch, aristocrat, holder of high-ranking military or political office, or other person possessing actual or ceremonial authority. The title has a history of use in West Asia, East Africa, West Africa, Central Asia, and South Asia. In the modern era, when used as a formal monarchical title, it is roughly synonymous with "prince", applicable both to a son of a hereditary monarch, and to a reigning monarch of a sovereign principality, namely an emirate. The feminine form is emira (أميرة ʾamīrah), with the same meaning as "princess".

Prior to its use as a monarchical title, the term "emir" was historically used to denote a "commander", "general", or "leader" (for example, Amir al-Mu'min). In contemporary usage, "emir" is also sometimes used as either an honorary or formal title for the head of an Islamic, or Arab (regardless of religion) organisation or movement.