Also an acronym to describe an annoying person/n00b in an online game or chat room.
James: Shut the hell up you are asdf!
1337 n00b: wha?
2. Four letters on a QWERTY-keyboard that are in a convenient row, and are thus easy to type for the purpose of spamming, receiving attention or expressing anger.
2. No I lost! asdf asdf asdf asdf...
(side not: the conversation below never actually happened, and the person named "trip" does not have a speech impediment, forcing him to talk like a complete idiot, hes is, above all, generally normal, and would not say this)
Ethan: wow. ASDF noob.
Ethan: What the hell is wrong with you? I told you to ASDF!
&this has to be the worst explanation you've read ;D you're welcome lolol.
"YES AY ES DE EF! geez man dont you know about asdf?...dont dis asdf it'll eat you."