Short for "compilation". Predominantly used on internet porn tube sites. "Pil" or "compilation" describes videos containing a collection of several short clips of one specific sexual act, fetish or genre shown back to back. These videos are useful when an individual want to view a certain type of pornography but does not care to view full scenes, i.e. foreplay to cumshot.
Popular "pils" include: facials, cumshots, blowjobs, handjobs, squirting, ect.