A state of being so stoned you unintentionally produce an erection. Whether or not this leads to arousal is unknown, but the man who produces the cannaboner is never ashamed of it.
John: ...
Bill: Wow, John sure it fucked up.
John: ...
Lynn: Yeah, cut him off. Wait, what's that bulge in his pants?
John: ...
Bill: Ha ha, he's got a cannaboner!
Lynn: I'm done too; I don't want to cannaqueef.