Following is an ‘official’ definition of the word arobasse:

@ (preposition)


Pronunciation: ['æt-sIn]
Definition: The "at" sign, used to mark the value or cost per item or to separate the user name from the domain name in an e-mail address.
Usage: For most of its history in the United States, the "at" sign has been used to refer to prices: "Today's Special—5 lb. potatoes @ $1." It's a humble job, but one that needs doing. With the advent of the technological economy, the @ sign lends its appropriate coded meaning to e-mail addresses the world over.
Suggested Usage: Linguists have compiled a list of names for the ubiquitous @ sign. European languages associate @ with animals. In Dutch, it's called apestaart "monkey's tail." In Finnish it's either kissanhäntä "a cat's tail" or miau merkki, transliterated "meow merk-key," a second-stage development of the @ sign's resemblance to a cat. Germans call @ a Klammeraffe "spider monkey" (literally, "clinging monkey"), and in Serbian, the word is majmun "monkey." To the Russians, the @ looks like the curled tail of a dog, hence their name sobachka "little dog." Some Swedes call it "Snabel-A" or "elephant-trunk A" while others prefer the culinary term, kanelbulle "cinnamon bun." In Hebrew opinion is again split between an animal and food: the sign in Hebrew is either ashablool "snail" or strudel. In French, @ is an "arobase" or "arobasse" from the Spanish "arroba" (see Etymology), or the "business a," though some French-speakers also see it as an escargot "snail," a sentiment shared by the Italians, who call it a chiocciola "snail."
Etymology: In 1972, the programmer Ray Tomlinson was working on a network addressing system that would clearly separate the username from the machine and domain identities. Tomlinson chose the @ because its meaning was widely known, it fit the use he had in mind, and because it never appears in a proper name. But the @ had been around a long time before the computer revolution. The @ in English probably originated with the French à in expressions like: ten apples a Euro = dix pommes à Euro. We may also have inherited it from Spanish or Portuguese, who used a similar sign for their "arroba" from the Arabic ar-roub "the quarter," a measure of solids and liquids. The evidence for either story is sketchy.
   
–Dr. Language, YourDictionary.com