Sampi (modern: ϡ; ancient shapes: Ͳ, Ͳ) is an archaic letter of the Greek alphabet. It was used as an addition to the classical 24-letter alphabet in some eastern Ionic dialects of ancient Greek in the 6th and 5th centuries BC, to denote some type of a sibilant sound, probably [ss] or [ts], and was abandoned when the sound disappeared from Greek. It later remained in use as a numeral symbol for 900 in the alphabetic ("Milesian") system of Greek numerals. Its modern shape, which resembles a π inclining to the right with a longish curved cross-stroke, developed during its use as a numeric symbol in minuscule handwriting of the Byzantine era. Its current name, sampi, originally probably meant "san pi", i.e. "like a pi", and is also of medieval origin. The letter's original name in antiquity i