Someone who attempts to convince people that they are a decent person while in reality they are complete sociopaths. A 'doster' will do anything to squeeze into every social circle they can only to be booted as soon as they are recognized or found out. Their only permanent friends are other dosters. They will use each other up and then continue to seek refuge in other circles. Dosters attempt to gain trust, and then use that to manipulate relationships and then squeeze them for whatever they may be worth. A dosters goal in manipulating can range from valuables such as cash and drugs, and undetected passage into another social circle so that the cycle may continue.
Guy1: hey, did you see the doster that showed up at the party last night?
Guy2: yea, someone recognized them and told them to go.
Guy1: thank god. We dont need any dosters trying to infultrate our group and start all that dramatic bull.
Girl1: i can't believe that girl stole my ipod and cash after i let her crash at my pad!
Girl2: I told you she was a doster.
Girl1: i really thought she was trust worthy!
Girl2: everyone does at some point. Thats why shes a doster!