Cain can be explained plainly as finishing off a drug quantity, whether it be a cannabis cigarette,
shesha bong or anything else of the sort.
Caining is to devour the last remains of something OR to devour it rapidly in quick
consession.
Example 1: Dude, that last pull was a real lung tickler, I'm out for the count, cain that shit.
Example 2: My Dad'll be home soon, let's cain his Jack Daniels before he gets home.
Example 3:
What ho! Those chicken nuggets are getting cained! I best get out a
fresh box for
yowl.