Green’s Dictionary of Slang

snug adj.

[SE snug, comfortable, cosy]

1. drunk.

[UK]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.
[UK]Farmer & Henley Sl. and Its Analogues.

2. (Aus.) smart.

[Aus]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.

[UK]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.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. 1725].
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]Cumberland Pacquet 9 July 4/4: ‘‘Sheepface and I will hold the back door open for you [...] and all’s snug’.
[UK]Era (London) 3 June 3/4: Sly old dog. I likes him for his cunning in keeping the whole thing snug.
[US]Matsell Vocabulum.
[US]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.