Slang term for amyl nitrite (not "nitrate" - this is a common misconception). Commonly used as a recreational drug to cause sensations of euphoria in conjunction with stimulant drugs and dance music. Alternatively used during sex to give feelings of disinhibition, as well as relaxing smooth muscle. It is sold in small glass bottles under such names as "Liquid Gold" or "Rush", and marketed as a "room odoriser". Its sale is not illegal in many jurisdictions.
Originally used as a treatment for angina (as it relaxes the muscles in artery walls), it came in small glass vials that were broken open (making a "popping" sound).
"Look at the poppers scabs on that dude's nose over there!"