To get slapped-out means to get told off or ridiculed verbally for getting something wrong, mainly from a boss/someone you’re doing something for.
It’s basically the vocal
equivalent of a slap
to the face.
This stems from the ideology that some parents have of slapping their kids as a form of punishment if they fall out of line,
eventually hoping to correct their behaviour. Hence the phrase “slapped-out”.
Henry: I got slapped-out by the boss today.
Mable: What happened this time?
Henry: I got the address wrong on today’s invoice and it never made it to his desk.
Mable: Probably just in a bad mood,
you should’ve seen how he slapped-out Charlie
the other day.
OR
Bob: My wife slapped me out
yesterday for staying at the bar too late.
Tom: I hate when my wife slaps me out man, I’d do anything to avoid it.