The ethnology Afghan has been used in the past to denote a member of the Pashtuns, and that usage still persists in some places in Afghanistan.
In the 3rd century, the Sassanids mentioned an eastern tribe called Abgân, which is attested in its Arabic form Afġān in the 10th century Ḥudūd al-ʿĀlam. Through the nineteenth century, the term "Afghan" was used by various writers as a synonym for "Pashtun", but such usage now is rare in English.
The name Afghanistan (Afghan+ -stan) is a derivation from the ethnonym Afghan, originally in the loose meaning "land of the Pashtuns" and referred to the Pashtun tribal areas south of the Hindu Kush mountains. so it is clear that Afghan mean Pushtoon and Afghanistan mean the land of pushtoon.
Since the Afghan Constitution of 1964, "Afghan" officially refers to every citizen of the state of Afghanistan, regardless which ethnic group the individual belongs to.
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