Green’s Dictionary of Slang

snug adj.

1. drunk.

1827		T. Morton A School For Grown Children II ii: sir a.: Where is your master? but.: Oh, snug! he’s invisible at the inn, if you want to see him.
1890–1904		Farmer & Henley Sl. and Its Analogues.

2. (Aus.) smart.

1880

Bulletin (Sydney) 22 May 4/4: He looks as snug and natty as ever, and ‘does’ Queen-street as jauntily as heretofore.

SE in slang uses

In phrases

all’s snug

all is quiet.

1725		New Canting Dict. n.p.: All’s snug; All’s quiet; used by Villains, when every thing is silent, and they hear no body stir to oppose their intended Rogueries.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1834		Cumberland Pacquet 9 July 4/4: ‘Sheepface and I will hold the back door open for you [...] and all’s snug’.
1849		Era (London) 3 June 3/4: Sly old dog. I likes him for his cunning in keeping the whole thing snug.
1859		Matsell Vocabulum.
1887		G. Davis Recoll. Sea-Wanderer 42: The lad thought that he had all snug, but Mr. Samuels had his eye on him all the time.