Derived from the pseudofrench word Pissoir:
Any publicly accessible restroom or toilet in any urban area where drug addicts can do their thing unattended while leaving the usual mess of needles and hepatitis infected blood stains.
Question: I really need to go. Is this the way to the restroom?
Response: Sorry, it's not a toilet. It's a fixoir! You don't want to go there, trust me! Go in your pants or find a quiet spot.