Used in order to communicate with others who are unaware of the fictitious and often highly constructed nature of the entity and their replies, so as to humiliate them at a later date.
The term can also be used as a verb in order to describe the process mentioned above, facilitated by adding a 'd' or 'ing' to the end of the word, often with several accompanying z's and x's in various combinations.
"Hey, who is this chick who just added me? Do you know her?"
"Sounds like an azn_kelz to me..."
"Bastards just azn_kelzdzx me"
"That's because you're retarded"