gassing, n. — Green’s Dictionary of Slang

gassing n.

[the image of throwing petrol, US gas, over a victim]

(US prison) throwing a liquid substance on an officer from a cell.

2000		Other Side of the Wall: Prisoner’s Dict. July 🌐 Gassing: Throwing a liquid substance on an officer from a cell.
2009		J. Stahl Pain Killers 10: Gassing is when a prisoner throws urine or feces at a guard.