Green’s Dictionary of Slang

excellent, wonderful, the best.

1824		Morn. Chron. (London) 21 Apr. 4/3: Gypsey, by his slashing hits, had the best in the first two or three rounds.
1826		Southern Reporter (Cork) 25 Mar. 4/1: In the cillars [sic] below dines the slashin’ young fellows.
1830		Egan Finish to the Adventures of Tom and Jerry (1889) 221: He met with a fine, slashing Yankee Black.
1841		A.M. Maxwell Run Through the United States I 157: We got into the train [...] and were hurried along at a slashing pace till we got to Ballston springs.
1841		Sporting Mag. Nov. 13: One of the most slashing races ever seen.
1842		S. Lover Handy Andy 18: He’s a slashing fellow.
1842		Whip & Satirist of NY & Brooklyn (NY) 2 Apr. n.p.: Lodge No. 3 [...] has been doing a slashing business in the jewelry line.
1843		Satirist & Sporting Chron. (Sydney) 18 Feb. 3/4: Some [...] Jim Crow evolutions took place last year, with enormous applause, but that was for a slashing price.
1848		Bell’s Life in Sydney 26 Feb. 1/4: I’ve got a slashing barrow.
1849		Paul Pry 23 Apr. 3/3: Tom H—e, alias the Slashing Butcher.
1850		(con. 1843) Melville White-Jacket (1990) 64: This slashing private also boasted that he could take a chip from between your teeth at twenty paces.
1857		‘Leary Man’ in ‘Ducange Anglicus’ Vulgar Tongue (1857) 42: To Covent Garden or Billingsgate / You of a morn must not be late, / But your donkey drive at a slashing rate, / And first be if you can.
1865		G.A. Sala My Diary in America I 53: That was the style in the good old days of ‘slashing’ writers.
1874		‘Old Calabar’ Won in a Canter III 87: A slashing fore and aft schooner.
1875		M. Thompson Hoosier Mosaics 59: So saying, he moved at a slashing pace down to the door of the Squire’s office.
1884		H. Smart Post to Finish I 86: The vagaries of a slashing iron-grey colt, the mounting of which even seemed no easy matter.
1889		Dead Bird (Sydney) 5 Nov. 1/1: A slashing fellow — Jack the Rip-her.
1889		Western Kansas World 19 Oct. 1/6: I’m going right in and have a slashing good time.
1890		H. Nisbet ‘Bail Up!’ 224: Venemous, perhaps, cowardly and relentless – yes, these were what he, in his cheque-valiancy, termed slashing.
1890		Nat. Police Gaz. (NY) 7 June 10/1: This was a slashing round. [...] Bowen gamely faced the music and fought Myer all over the ring.
1895		Mirror of Life 3 Aug. 11/2: [A]fter a slashing fight Fowler knocked his man out.
1900		Nat. Police Gaz. (NY) 5 May 7/2: They peppered away [...] at a slashing pace.
1901		‘Miles Franklin’ My Brilliant Career 149: You’re a very slashing little concern, but you are not big enough to do much damage.
c.1905		J. Furphy Rigby’s Romance (1921) Ch. xxx: 🌐 My ole man, he’s got a slashin’ farm not eighty miles from where we’re sitting.
1905		A. Binstead Mop Fair 143: A great, slashing colt like this.
1910		Wodehouse Psmith in the City (1993) 126: Not what one would call a slashing victory.
1913		Sport (Adelaide) 11 Jan. 13/3: They Say [...] That Jerry P., the well-known; Channel swimmer, was going strong on Friday night with two slashing tarts.
1923		Mirror (Perth) 29 Sept. 4/2: Coffey scored a slashing goal with a lovely drop-kick.
1937		R. Westerby Wide Boys Never Work (1938) 147: She was a slashing tart all right.
1944		L. Glassop We Were the Rats 35: I’ve got a couple of slashing lines who’ve come from Sydney for the Mayoral Ball. They’re a couple of pushovers.
1957		‘Nino Culotta’ They’re a Weird Mob (1958) 46: In addition to being ‘fabulous drops’ these were also ‘slashing lines’.
1968		D. O’Grady A Bottle of Sandwiches 210: ‘There’s some pretty good targets about.’ ‘Some pretty slashin’ lines, too.’.
1985		B. Robinson Aussie Bull 34: [T]he slashing blonde wearing the see-through blouse and the mini-skirt .