At sign

The absence of a single English word for the symbol has prompted some writers to use the French arobase,[2] Occitan arròba and Aragonese, Catalan, Portuguese and Spanish arroba, or to coin new words such as ampersat[3] and asperand,[4] or the (visual) onomatopoeia strudel,[5] but none of these have achieved wide use.

The earliest yet discovered symbol in this shape is found in a Bulgarian translation of a Greek chronicle written by Constantinos Manasses in 1345.

Held today in the Vatican Apostolic Library, it features the @ symbol in place of the capital letter alpha "Α" as an initial in the word Amen; however, the reason behind it being used in this context is still unknown.

It has long been used in Catalan, Spanish and Portuguese as an abbreviation of arroba, a unit of weight equivalent to 25 pounds, and derived from the Arabic expression of "the quarter" (الربع pronounced ar-rubʿ).

[9] A symbol resembling an @ is found in the Spanish "Taula de Ariza", a registry to denote a wheat shipment from Castile to Aragon, in 1448.

[10] The historian Giorgio Stabile claims to have traced the @ symbol to the 16th century, in a mercantile document sent by Florentine Francesco Lapi from Seville to Rome on May 4, 1536.

It could also mean “adi” (standard Italian “addì”, i. e. ‘on the day of’) as used on a health pass in Northern Italy in 1667.

When included as part of a person's or company's contact details, an @ symbol followed by a name is normally understood to refer to a Twitter handle.

[16] In Internet Relay Chat (IRC), it is shown before users' nicknames to denote they have operator status on a channel.