Green’s Dictionary of Slang

gow n.1

also ghow
[Chinese yao-kao, opium; ult. yao, drug + kao, an oily, fatty substance, esp. an unguent]
(US drugs)

1. alcohol.

[US]B. Fisher A. Mutt in Blackbeard Compilation (1977) 134: When the provider comes home after a hard day [...] lead him to the sideboard, get him full of gow and when totally unconscious extract the bank roll. [Ibid.] 141: Do you think that a shot of gow would help?

2. opium, heroin or morphine.

[US]DN V 182: Opium [...] Gow.
[US]J. Black You Can’t Win (2000) 134: You’re in with what ‘gow’ I’ve got.
[US]Ersine Und. and Prison Sl. 39: ghow, n. Opium.
[US]B. Dai Opium Addiction in Chicago 199: Gow. Drugs in general.
[US]Anslinger & Tompkins Traffic In Narcotics 309: gow. Drugs, especially opium.
[US]J.E. Schmidt Narcotics Lingo and Lore 67: Ghow – Opium; an opiate.
[US]R.R. Lingeman Drugs from A to Z (1970).
[US]E. Bunker No Beast So Fierce 81: ‘You got some ghow?’ ‘Two grams in my mouth.’.
[US]E. Bunker Mr Blue 256: Pepper loved junk, smack, ghow, heroin.
[US]Other Side of the Wall: Prisoner’s Dict. July 🌐 Chiva: Heroin (Spanish). Also: scam, gow, stuff, hop.

3. attrib. use of sense 2.

[US] (ref. to 1898) N. Kimball Amer. Madam (1981) 272: There’s always the danger she’d bring her pipe and gow pills with her and give the habit to the other girls.
[US](con. 1870s) S. Longstreet Pedlocks (1971) 69: He had rolled the little gow hop pill of opium, cooked it on the end of a pin over the little ken-ten lamp made of a sardine tin.
[US]Cressey & Ward Delinquency, Crime, and Social Process 820: I can [...] make money from the weed man, the crystal man, and money from the gow (heroin) man too.

4. an opium pipe.

[US]A.J. Pollock Und. Speaks n.p.: Humming gay [sic] a favorite opium pipe bowl that purrs and sizzles during the process of cooking opium.
[US]Monteleone Criminal Sl. (rev. edn) 97: ghow An opium pipe.
[US]Anslinger & Tompkins Traffic In Narcotics 308: ghow. An opium pipe.

5. a pleasurable drug experience.

[US]Lait & Mortimer N.Y.: Confidential 119: White women learned where they could get a ‘belt,’ a ‘jolt,’ or a ‘gow’.

In compounds

gow job (n.) [? SE go or fig. use of sense 2 above + job n.2 (2)]

1. (US campus) a flashily dressed girl or woman.

[US]Life May 15 68: A ‘gow job’ (flashy girl) wears at least two [i.e. hair clasps].

2. (US) a ‘hot rod’ car modified for high performance.

[US]Life 5 Nov. 87: A ‘hot rod,’ also called a ‘hot iron,’ or a ‘hot-up’ or ‘gow job,’ is an automobile stripped for speed and pepped up for power until it can travel 90 to 125 mph.
gow joint (n.) [joint n. (3a)]

(US prison) an opium den; a place where narcotics are sold.

[US]D. Clemmer Prison Community (1940) 332/2: gow joint, n. A place where opium is smoked, or any place where any narcotic is sold.

In phrases

hit the gow (v.)

(drugs) to smoke opium.

[US]D. Maurer ‘Junker Lingo’ in AS VIII:2 27: When one has contracted the habit or is under the immediate influence of the drug, he is all lit up, on the gow, or hitting the gow.
[US]Monteleone Criminal Sl. (rev. edn).
[US]J.E. Schmidt Narcotics Lingo and Lore.