A substance, image, situation, or thought that destroys an otherwise steadfast boner.
Man, I was messing around with this girl the other night, and for some reason, I thought of the time I saw these two bums fucking in a dumpster and the Boner Poison hit...
Noun: Someone/something that ruins a pristine moment or generally shits all over what was supposed to be a good moment.
Verb: (Poisoning one's boner) the act of being boner poison.
Noun: Drake was total Boner Poison when he only took one vicodin, leaving me one pill short of what shouldve been an amazing high.
Verb: By taking only one vicodin, Drake poisoned my boner.