Top definition
A slang term used to describe black tar heroin.
"Hey Jimmy, Wanna go burn some royal oil by the dumpster behind the Thrift Store?"
by That little voice in your head November 10, 2009
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug