From The Free On-line Dictionary of Computing (19 January 2023):
commercial at
@
at sign
<character> "@". ASCII code 64. Common names: at sign, at,
strudel. Rare: each, vortex, whorl, INTERCAL: whirlpool,
cyclone, snail, ape, cat, rose, cabbage, amphora. ITU-T:
commercial at.
The @ sign is used in an electronic mail address to separate
the local part from the hostname. This dates back to July
1972 when Ray Tomlinson was designing the first[?] e-mail
program.
It is ironic that @ has become a trendy mark of Internet
awareness since it is a very old symbol, derived from the
latin preposition "ad" (at).
Giorgio Stabile, a professor of history in Rome, has traced
the symbol back to the Italian Renaissance in a Roman
mercantile document signed by Francesco Lapi on 1536-05-04.
In Dutch it is called "apestaartje" (little ape-tail), in
German "affenschwanz" (ape tail). The French name is
"arobase". In Spain and Portugal it denotes a weight of about
25 pounds, the weight and the symbol are called "arroba".
Italians call it "chiocciola" (snail).
See @-party.
(2003-04-28)