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Drinking an entire bottle of cough syrup in order to get high. This is because the active ingredient in cough syrup is codeine, a morphine derivative.

Named after Robitussin, a brand of cough syrup.

WARNING: Causes seriously bad trips much more often than good.
Jack: Hey, those guys are doing tussin, let's join in.
Jill: No way man, I ad a fucking nasty experience last time I did that. I'd seriously rather eat shit.
by Darth Ridley November 01, 2006
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