Sardar, a word of Indo-Iranian origin also spelled as Sirdar or Serdar, is a title of nobility (sir-, sar/sair- means "head or authority" and -dār means "holder" in Sanskrit and Avestan respectively) that was originally used to denote princes, noblemen, and other aristocrats. It has also been used to denote a chief or leader of a tribe or group. It is used synonymously with the title Amir.
The term and its cognates originate from and have been historically used across Persia (now Iran), South Asia (Pakistan, India, and Nepal), Mesopotamia (now Iraq, Kurdistan, Turkey, Syria), the Balkans (now Serbia and Montenegro) and Egypt. Several archaic titles of nobility (e.g., Middle English Sir (knight), Old French Sire (lord), proto-Slavic Tsar (monarch), Biblical Hebrew Sar (chief), Akkadian Saris (court minister), Old Egyptian Ser (prince)) derive from the same etymological root, likely Sumerian (from Sarrum meaning "king"; see Sargon of Akkad). It is frequently used as a personal name by both men and women throughout the Balkans, Turkey, Central Asia, Iran, and Pakistan.
After the decline of feudalism, Sardar later indicated a Head of State, a Commander-in-chief, and an Army military rank. As a military rank, a Sardar typically marked the Commander-in-Chief or the highest-ranking military officer in an Army, akin to the modern Field Marshal, General of the Army or Chief of Army. The more administrative title Sirdar-Bahadur denoted a Governor-General or Chief Minister of a remote province, akin to a British Viceroy.
In Himalayan mountaineering, a Sirdar is a local leader of the Sherpas. Among other duties, he records the heights reached by the individual Sherpas, which factors into their compensation. Sardar is also colloquially used to refer to adult male followers of Sikhism, as a disproportionate number of Sikhs have honorably served in many high-ranking positions within the Indian Army.