Green’s Dictionary of Slang

nod n.1

1. [late 17C+] (20C+ use US black) a sleep.

2. [1930s+] (orig. US drugs) the drug-induced stupor or semi-sleep that follows an injection of heroin.

In compounds

nod-box (n.)

[1940s] (US black) a bedroom.

Nodland (n.)

[1970s] (US) a state of sleep.

In phrases

collar a nod (v.)

[1940s] (US black) to sleep, to take a nap.

cop a nod (v.) (also cop a snooze)

1. [1930–70s] (US) to have a nap, to go to sleep.

2. (US drugs/prison) to become intoxicated and initially comatose after injecting a narcotic.

go on the nod (v.)

[1950s] (US) to die.

knock a nod (v.)

[1930–40s] (US black) to have a sleep.

on the nod [1950s+] (drugs)

1. succumbing to a sleepy stupor after smoking opium or taking an injection of heroin.

2. dozing off after smoking cannabis.

3. falling sleep, exhausted from excess of any sort.

4. see also SE phrs. below.

play the nod (v.)

[1930s–50s] (drugs) to doze off as a result of injecting a narcotic drug.

SE in slang uses

In phrases

on the nod [the shop-owner nods his assent to one’s request]

1. [late 19C+] on credit.

2. [late 19C+] without argument, typically of Parliamentary or local government business which ‘goes through’ or ‘passes on the nod’.

3. [late 19C-1920s] for free.

4. see also sl. phrs. above.