A state of lethargy that prevails while engaged in activites involving a computer or cell phone. often results in falling over onto the keyboard of the computer/phone and sleeping for a long period of time while one's buddies on chat constantly message them asking where they went, or where an excessive amount of texts are recieved also questioning them. Usually, no answer is given due to the slumber the plopper is in, resulting in buddies feeling as though their friend has been abducted by aliens.
Dude, sorry I never responded to your IMs last night. I plopped and ended up being late to school.
(Into an AIM chat): I'm so tired, I'm probably going to plop any minute. Don't be surprised if you get some mumbo jumbo IMs from me, its probably my forehead.