The male form of "Retardijuana". Someone who acts high all the time even when they are not. Someone who laughs at everything, even if it is not funny at all.
Person 1: "Why is Billy foaming at the mouth, making weird noises, being abnormally hyper, and laughing at things that aren't funny at all?"
Person 2: "I don't know...maybe he's high?"
Person 3: "Billy wouldn't be high, he's just a retardijuano!"