Definition
Any beverage of low quality.
Origins
From cat + piss. The marijuana sense is from the perceived resemblance of the smell.
How People Actually Use It
marijuana that smells extremely bad, hence the name. but we all know if it smells bad it’s going to be a good high
"What is you smoking? Cat piss - Ski Mask the Slump God and Lil Yachty"
Source: Urban Dictionary