Same as fluffer; person on porn movie set whose job it is to keep male cast erect by providing oral sex.
The plater wasn't good enough at her oral craft to keep Sir Fuxalot hard enough for his next scene.
2 more definitions
a retard; one who usually is suckish at gaming.
Dude! That guy is such a plater at WoW
A chick that has perfect boobs; ones that u can sit down on a table plater
Damn that feezie got some platers