Abbreviation of "halfway decent," meaning good, okay, or all right, often when there was a lower expectation. Somewhere between clutch and meh.
Joe: What'd you think of Avatar?
Suzy: It was half dubs dece, though the Pocahantas shit was a little overdone.
Joe: Fuck you I thought it was da shit.
Suzy: Totes whatevs. Wanna get some chicken selects?
The moment in an online conversation when people stop reading the comments above and thus repeat them, annoying the original poster and everyone who commented before.
This thread has reached its Debus point—people keep repeating things that have already been said, and I’m super annoyed.