Green’s Dictionary of Slang

lay n.5

1. [1910s–30s] (US) a place to sleep, a bed.

2. [1920s–50s] (US drugs) the act of lying down and smoking opium.

3. [1930s] (US drugs) a session in an opium den.

4. [1930s] (US drugs) a portion of any type of drug.