Sardonic: Grimly mocking or cynical (adj)
Redonkulous: Significantly more absurd than ridiculous to an almost impossible extreme; without possibility of serious consideration (adj)
Sardonkulous: Ridiculously cynical, absurdly mocking, sardonic to the extreme (adj)
Matt: You'll be trafficking in sex slaves next.
Jess: Dude! Too far. That's sardonkulous.
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Jess: GET OUT!
Matt: Man, you're being sardonkulous
when something is so ridonkulous, so that the ridonkulousness of it is multiplied by three, or, in other words, tripled. thus, it is not just ridonkulous, but TRIdonkulous. the "tri" signifies the triple nature of the ridonkulousness.
karl: shit did you see pyramid that kid made out of orangina bottles?
jay: that was ridonkulous.
karl: no man. that was beyond that. that was TRIDONKULOUS.