A symbol standing for the word "at" that in turn symbolizes lazyness and stupidity. I mean, seriously, who sat down and thought up a symbol to shorten a two letter word? WHY? Your time could be better spent counting blades of grass in your front lawn. At least that might teach the retarded bastard to count! If you now anyone that abbreviates the word "at" as "@", cease all conversations with said person, as their retardedness may rub off on you.

to sport a boner, fly the sail at full mass, rock hard, etc.

When someone calls you out but indirectly and you notice on social media like Facebook or Twitter

on UNIX system, used as a character between the username and the hostname.
Pronounced like 'at'.

a character between user and the computer or network name in an email address.

A symbol meaning at usually placed between the user name and the domain name.

the @ symbol, for when the ! symbol doesn't show your true excitement