The act of getting fucked up and not knowing what else to say because your brain is physically not functioning from the inhalation of marijuana/other recreational drugs and/or alcohol. Also used to describe anything and everything that you happen to find funny during that said time. It can also replace the word JK (see ex)
Geoff is about to shoot a beer pong shot.... "SHPLAPPERS"!
Paul: I just took a hit off that bubbler, damn I feel good... "SHPLAPPERS"!
Miller I hate your guts!... "SHPLAPPERS"!