An aych p is a persie hit of 80% marijuana and 20% tobacco (from a gutted out blunt, or, for the more refined smoker, fine cavindish) from a bong. It gives you an awesome nicotine head rush as well as an amazing chronic high.
"Whatd u do last night homie?"
"Me and ur boy just chilled and did aych p's all night"
"Word? Did homeboy throw up again"
"Haha Na he was good"