flash blood
n.— «Many injecting drug users share dirty needles or use a dangerous cash-saving technique known as “flash blood,” in which a user injects heroin or another illicit substance and then draws a syringe full of blood that is passed to a second user to inject.» —“Escalating drug use threatens AIDS fight” in Stone Town, Tanzania PlusNews Global July 27, 2007. (source: Double-Tongued Dictionary)
Further reading
When Kentrell from West Memphis, Arkansas, worked for a granite company, his co-workers who were about to put two pieces of granite together would say I’m going to pull a seam. But why would they use the word pull for the action of pushing...
A flashlight doesn’t flash. It provides a steady beam of light. So why is it called a flashlight? The earliest versions lit up only briefly before the batteries gave out and required a recharge, so they were literally “flash lights...