A "doobie" is a slang term used for a marijuana cigarette. The word is derived from the latin term dubiety which could mean 1 : giving rise to uncertainty: questionable or suspect as to true nature or quality. And when u smoke a doobie, it alters your perception, giving u a false sence of reality, leaving things uncertian and questionable. Look at the english root of the word "Dubious". It means doubt, uncertianty or questionable in nature. So Its safe to say a "doobie" is the means of which one will bring uncertianty or perception. thru smoking something that deviates from or perverts the truth. Marijuana.
You have no idea what you're talking You have no idea what you're talking about. Your reasoning is absurd. The word could have just as easily arrived from terms like "dubout. Your reasoning is absurd. The word could have just as easily arrived from terms like "duplication" "duality" or any other word that starts with "du" or "do". In all likelyhood it was probably just made up on the fly by someone who was smoking it, and it doesn't have any significant etomological meaning. You should engage in the consumption of some marijuana, because for a sober person who insists that they have a firm grasp of reality you seem pretty tense, not to mention uneducated.