Green’s Dictionary of Slang

of features, neat, well-formed; of dress, neat, spruce.

1569–70		T. Preston Cambyses B3: Gogs hart slaue dost thinke I am a sixpeny Jug: No wis ye Jack I looke a little more smug.
1577		Misogonus in Farmer (1906) II ii: By the mass! I know her, she is a good smugly lass.
1599		G. Peele Sir Clyomon and Sir Clamydes in Dyce (1861) 516: There’s neighbour Nichol’s daughter, a jolly smug whore with vat cheeks.
1611		Davies of Hereford Scourge of Folly 67: Young girles (he saith) his old-cold flesh doth cheere And maks the same to looke most smooth, and smugge.
1616		W. Haughton English-Men For My Money I 2: She is a sweete smugge Girle.
1631		J. Shirley School of Complement III ii: ’Tis a pretty smug Wench.
1639		R. Davenport New Tricke to Cheat the Divell III i: A smug Lasse, And one that knowes it too.
1675		F. Fane Love in the Dark IV i: Why, Husband; pretty smug-fac’d Husband, did not I know thee?
1688		J. Shirley Triumph of Wit 116: Kind Jenny, it rejoices me to see how smug you are in they Neatness that has often made my Chaps Water, I’ll assure you.
1694		J. Eachard (trans.) Plautus’s Rudens II vi: What luck’s here? – ’S bobs, as I hope to breath, a smug-fac’d Rogue!
c.1698		B.E. Dict. Canting Crew n.p.: Smug [...] neat and spruce.
1700		‘The Tunbridge Doctors’ in Playford Pills to Purge Melancholy II 161: For they’ve a new Drug / Which is call’d The close Hug, / Which will mend your Complexion, / And make you look smug.
1725		New Canting Dict. [as cit. c.1698].
1805		J. Reynolds Blind Bargain I i: Hav’n’t you been lately coquetting with a certain smug alderman?
1859, 1860		Hotten Dict. of Modern Sl. etc.
1873		Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 8: Smug - Sleek, in fashion.
1895		Crowe Aus. Sl. Dict. 76: Smug, neatness.