Green’s Dictionary of Slang

1. (orig. US) a fortifying alcoholic drink.

1848		‘Ned Buntline’ Mysteries and Miseries of N.Y. I 64: The two villains at once sent a pale, sickly looking girl [...] out to Ma’am Buckley for a stiff’ner each, of grog.
1860		Bell’s Life in Sydney 11 Aug. 3/4: Ryan ungenerously insinuated that Nutt’s libations having affected his ‘nut,’ he saw not double, but twenty fold, and counted as a ‘couter’ the ‘bob’ he had spent in ‘stiffners’.
1864		J. Armour Diggings, the Bush, and Melbourne 14: They adjourned to the tap-room for a ‘stiffener’.
1865		Leaves from Diary of Celebrated Burglar 33/1: In we went to a neighboring public house, and calling for a stiffener of brandy each, had it to our lips when we overheard the words.
1909		Truth (Brisbane) 10 Oct. 12/7: l [...] called for a stifTener of rum and tossed it down mv neck.
1912		Bulletin (Sydney) 12 Dec. 30/4: Then the mob, breathing freely once more, breasted the bar and called for stiffeners.
1938		H. Drake-Brockman Men Without Wives II i: I had to get me a stiffener half way through.
1948		R. Park Harp in the South 146: ‘I’ll bet Hughie’s got a few under his belt. Ain’t like him to carry a pall without getting in a few stiffeners first,’ .
1953		L. Doyle Back to Ballygullion 131: Andy fetched him a stiffener in a wee bottle.
1956		A. Upfield Battling Prophet 16: If Ben didn’t come out from them funny sort of hoojahs pretty quick, I’d break our rule and give him a stiffener to keep him going.
1962		E. Lane Mad as Rabbits (1973) 61: The woman had apparently turned back for a stiffener [...] and had never reached the phone.
1965		(con. 1940s) B. Behan Confessions 22: By the time they’d got a few stiffeners into themselves and us.
1979		J. Morrow Confessions of Proinsias O’Toole 128: I dropped into the Prince for a stiffener or two.
1998		C. Olson Krøyer 146: The regular lifeboat crew then gathers in the ‘Harbour’, as the hotel's taproom is called, and after a quick stiffener they race down to the shed .

2. a shock.

1877

H. Hartigan Stray Leaves (1st ser.) 155: He was [...] sentenced to be marked with the letter ‘ D.,’ to undergo 184 days’ imprisonment with hard labor, and to ‘be put under stoppages not exceeding two-thirds of his daily pay [...]’ There was a stiffener for you!

3. (Aus.) a hard puncher.

1902

‘Banjo’ Paterson ‘Saltbush Bill’s Second Fight’ in Rio Grande’s Last Race (1904) 81: But, Boss, you’d better not fight with me, it wouldn’t be fair nor right; / I’m Stiffener Joe, from the Rocks Brigade, and I killed a man in a fight.

4. (Aus.) in horseracing, a horse that has been doped (for speed or to slow it down); thus the individual who administers the drugs.

1909		Sun. Times (Perth) 28 Feb. 4s/7: ‘This stiffener was in the bag,’ / Explains one flattened pea.
1910		Sun. Times (Perth) 23 Jan. 2nd sect. 2/3: He is said to be a holy terror to the evil-doers — the stiffeners, the stuffers, the whole corps d’armee of wrong ’uns.

5. (US) a pornographic novel.

2011

(con. 1950s) H. Ellison Introduction in Pulling a Train’ [ebook] One-handed reading material, intended to keep truck drivers entertained in roadside toilets. In the trade we called them ‘stiffeners’.

6. as sense 1, but with ref. to cannabis.

2005

B. Hare Urban Grimshaw 86: The girl on my right came round and began to prepare another stiffener [i.e. a pipeful of cannabis].