Green’s Dictionary of Slang

1. stylish, fashionable, i.e. knowing what is in style .

1671		‘L.B.’ New Academy of Complements 257: But yet those Citts are subtil slaves, / Most of them Wits, and knowing Knaves.
1742		Account of Behaviour, Confessions, and Dying Words 10/1: His Son Thomas would never follow the Steps of his Father [...] he would be sure to be at every Publick Place where young People in low Life resorted, and no one more affected to dress like a Knowing One than he did.
1791		W. Reeve ‘Tippy Bob’ song in Bluebeard [pantomime] I’m [...] the knowingest smart of the town.
1793		Sporting Mag. Mar. I 349/1: Your pocket may be picked with the consolatory sensation of being thought a knowing-one.
c.1805		‘The Rage’ in Jovial Songster 19: Thus the rage is the rage: if it hides or reveals, / So ’tis jemmy and natty and knowing.
1811		Austen Sense and Sensibility (1970) 88: Many young men, who had chambers in the Temple made a very good appearance in the first circles, and drove about town in very knowing gigs.
1812		Spirit of Irish Wit 141: A‘h! by St Patrick, the English girls I see are knowing ones’.
1818		W. Perry London Guide 45: Strangers to town in particular should be careful not to let others know what money or valuables they carry [...] and the town-bred knowing ones too, had better profit by the advice.
1824		‘Sonnets for the Fancy’ Egan Boxiana III 621: A very knowing rig in ev’ry gang, / Dick Hellfinch was the pick of all the slang.
1827		Australian (Sydney) 4 July 3/3: Each gentle and simple flat and knowing ’un.
1830		Egan Finish to the Adventures of Tom and Jerry (1889) 179: The thief, observing the Knowing Cove in the act of praying [ etc.].
1833		C.A. Davis Letters of Major J. Downing (1835) 34: Zekil is a knowin cretur.
1849		C. Kingsley Alton Locke (1850) 70: By Jove, Alton, my boy! you’re a knowing fellow [...] to rise two beauties at the first throw, and hook them fast!
1849		Life in Boston & N.Y. (Boston, MA) 1 Sept. n.p.: [We] should be happy to receive some information [...] from any of the ‘knowing ones’.
c.1864		A. Stephens ‘The Chickaleary Cove’ 🎵 I have a rorty gal, also a knowing pal, / And merrily together we jog on.
1877		J. Greenwood Dick Temple I 23: A knowing blade who is well up to those more or less shady amusements.
1880		Bulletin (Sydney) 19 June 3/2: A weak-kneed, slab-sided, undergrown, off-shoot of humanity with a strong admixture of idiocy and cunning marked on his frontispiece has of late been exercising the knowing ones of Brisbane.
1897		Truth (London) 10 June 35/1: ‘As for the ’at, I couldn’t get that knowin’ tip of ’is no’ow’ ’.
1905		‘The Overlander’ in ‘Banjo’ Paterson Old Bush Songs 119: For I’m a regular knowing card, / The Queensland overlander.

2. aware, ‘street-wise’, often as knowing one, a stylish, well-informed person, an ’insider’, often in context of sports gambling; thus the quality of knowingness.

1748		Spy on Mother Midnight I 28: The Knowing Ones are better pleas’d with a Yorkshire Hunter of a middle size, which I take to be seven, or, at most, eight inches.
1781		Hicky’s Bengal Gaz. 1-8 Dec. n.p.: The knowing ones are very doubtful of her.
c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Knowing Ones Persons on the turf, who from experience and an acquaintance with the jockies, are supposed to be in the Secret, that is, acquainted with the true merits or Powers of each Horse; notwithstanding which it often happens that the knowing ones are taken in.
1788		Grose Classical Dict. of the Vulgar Tongue (2nd edn) n.p.: knowing ones Sportsmen on the turf, who from Experience & an Acquaintance with the Jockeys, are supposed to be in the secret, that is, to know the true merits or powers of each horse; notwithstanding which it often happens that the knowing ones are taken in.
1794		Sporting Mag. June IV 180/1: Brother bruisers mourn! / Ye knowing kiddies hover round his urn!
1800		Sporting Mag. Dec. XVII 143/1: The opinion of the knowing-ones was decidedly in favour of Belcher.
1822		Sydney Gaz. 20 Sept. 1/2: Nobody can doubt Miss Lydia's shrewdness after the specimen she has given of her twelve months proficiency in the Botany slang; knowing cove, the bush, &c.
1828		‘A Flat Enlightened’ Life in the West I 49: [A] few hints from a ‘knowing’ friend, [...] convinced him that there must be ‘a way’ to bet with a certainty of winning.
1832		Spirit of the Times (NY) 4 Feb. 3/1: It [i.e. tobacco smoking] will to the ‘knowing ones’ [...] account for the breaking off of three ‘splendid matches’ [...] in our first circles.
1835		Sydney Herald 18 June 4/2: [B]low me if it warn’t capital, you [...] gammoning the knowing ones till the Recorder almost gave in, and the lawyers almost returned the brads.
1840		London Mag. Feb. 18/1: Fox the lawyer vindicated the aptitude of the name he bore by [...] mental acuteness, allied to the more vulgar faculty of ‘knowingness,’ which the angular sharpness of his features, and his rather small and piercing eyes, very faithfully reflected.
1842		Whip & Satirist of NY & Brooklyn (NY) 30 July n.p.: Many of the promoters of the ring as well as a number ‘knowing ’uns’ were present .
1845		Hereford Times 22 Mar. 3/7: The poor, unsuspecting youth, being completely taken up with the pony, together with the flash slang of the knowing one, of course believed all he said.
1846		Bell’s Life in Sydney 10 Jan. 2/2: This important mill which has terminated otherwise than had been anticipated amongst our knowing ones.
1850		Manchester Spy (NH) 5 Oct. n.p.: We would like to be informed by the ‘knowing ones’ what kind of a log-rolling affair [...] the little lawyer intends getting up.
1864		Derby Day 39: Ted’s tip was worth all the tips of prophets, touts, and ‘knowing ones’ put together.
1880		G.F. Northall ‘Momus’ Misc. 60: His owner was a knowing un’ wot hanged about in pubs.
1889		Music Hall & Theatre Rev. 23 Feb. 21/2: His festive lordship and ‘The Squire’ are such a pair of exceedingly knowing cards.
1900		Marshall W. Taylor Fastest Bicycle Rider in the World (1928) 145: It was generally conceded by the ‘knowing ones’ that the Major had a cinch.
1907		Times Dispatch (Richmond, VA) 30 June 35/3: But what cared they, the Jolly Dogs. / They thought they were quite knowing.

3. (UK Und.) a confidence trickster; anyone ready to exploit a gullible victim.

1748		G. Williams in Jesse George Selwyn (1843) I 127: I say, shun the knowing ones, and abstain from hazard.
1775		K. O’Hara Two Misers I i: Why, Squander, the young merchant, fallen in at hazard yonder with some knowing ones, is fleeced, done up to the last shilling.
1801		Daily Advertiser (N.Y.) 27 Jan. 3/1: A line addressed for ‘the Knowing Kiddy, to the care of Callender at the Penitentiary Jail,’ will receive immediate attention.
1821		Egan Life in London (1869) 184: In flattering yourself that you are knowing [...] make an allowance that there are to be found in company persons as knowing as yourself, if not more knowing!
1822		Westmorland Gaz. 7 Sept. 4/5: There were to be found [...] knowing-ones [...] and those who entrap the most scientific, either at cribbing a tattler or a fawney.
1833		‘Knowing Bill’ in Rake’s Budget in Spedding & Watt (eds) Bawdy Songbooks (2011) III 86: All the flash coves in Covent Garden knows me, and calls me Knowing Bill, because I’m down to every move, up to every sharp, fly to every trick and awake to all their slum.
1857		‘Leary Man’ in ‘Ducange Anglicus’ Vulgar Tongue (1857) 42: The fakement conn’d by knowing rooks / Must be well known to you.