Green’s Dictionary of Slang

whacky adj.

also wack, wacky, whack
[Yorks. dial. whacky, a fool, a simpleton, a blockhead; also Warwickshire dial. whacky, left-handed]

1. (orig. US) eccentric; as n. in cite 1849.

[UK]Paul Pry 30 Apr. 3/1: Come, come Andrew [...] Allow the old woman to clean your house and wash the children; and, like a man, operate in your own business. Be up and stirring, you old whacky.
[US] (ref. to late 19C) N. Kimball Amer. Madam (1981) 94: It also taught me to be wary of a whacky dangerous guest, for Frenchy told me there were signs to recognize a john who was off his trolley.
[US]Pic (N.Y.) Mar. 7: Nothing disgusts players of gut-bucket, screwball, and whacky music so much as the Schmaltz or sweet type played by a ‘Long-Underwear gang.’.
[US]A. Bessie Men in Battle 269: He’s wacky [...] shell-shocked.
[US]R.L. Bellem ‘Monster’s Malice’ Dan Turner – Hollywood Detective May 🌐 ‘Are you plastered or plain wacky?’ I asked him. ‘I’m not drunk. [...] But if by wacky you mean insane, I’m afraid the answer is yes. You see, I — I think I’m losing my mind.’.
[US]I. Shulman Amboy Dukes 99: You’re becoming even whackier than you are.
[US]T. Runyon In For Life 89: Most of us must have gone just a little whacky.
[US]‘John Eagle’ Hoodlums (2021) 119: [in context of drug use] ‘Just wacky on that squirrel powder’.
[US](con. 1948) C. Chessman Cell 2455 284: The story’s just wacky enough to be true.
[UK]K. Waterhouse Jubb (1966) 24: Britain’s whackiest boozer, they call it [...] He’s mad, is that landlord.
[US]L. Bruce How to Talk Dirty 21: Other guys had gone wacky.
[US]E. Torres Carlito’s Way 24: She was just a kid and very whacky.
[UK]A. Sayle Train to Hell 128: I’m sure you’ll find some wacky funny Jewish humour in what he has to say.
[Aus]Bulletin issues 5626-33 92/2: ‘Whacky’, which has to do with the number of kangaroos loose in the top paddock.
[US]P. Cornwell Cause of Death (1997) 116: I’m beginning to think the guy was wacky.
[US]Eble Campus Sl. Fall 9: wack, or whack – awry, unusual.
[UK]Observer Screen 23 Jan. 7: One is the beginning, which is so whacky it seems like a trailer for another [...] feature.
[Ire]P. Howard Curious Incident of the Dog in the Nightdress 277: He [...] is a bit, I don’t know, wacky.
[US]T. Dorsey Riptide Ultra-Glide 182: The wacky stories we have in our state’s history!
[UK]Guardian G2 10 May 11/1: This is just a whacky idea I had [etc].

2. obsessed, passionate about.

[US]A. Kapelner Lonely Boy Blues (1965) 53: One general was simply wacky over me, proposed to me every time he had me in the dark!

In derivatives

whackiness (n.) (also wackiness)

eccentricity.

[US]W. Winchell On Broadway 19 Sept. [synd. col.] Cliff Navarro and Colonel Stoopnagle traded wackiness and double talk the other eve.
Amer. Record Guide XV 160: These are not samples of Spike’s best brand of whackiness, but they are amusing.
[US]Billboard 4 Aug. 52/3: Burke had his first taste of Hollywood’s whackiness soon after his arrival on the coast.
[US]Baseball Digest May 58: This whackiness, intended or otherwise, has helped the baseball fan not only to survive but to keep coming back despite awesome obstacles and deterrents.
J. Vermilye Cary Grant 59: Grant, Young, and Miss Bennett sustained an inspired level of sophisticated whackiness.
C. Molesworth Donald Barthelme’s Fiction 81: Amateurs [...] returns in part to the sense of whackiness that was a staple in the earlier volumes.
L.A. Poague Another Frank Capra 26: And the primary agency of unity, on Bergman’s reading, was a quality of ‘whackiness’ deriving from the ‘screwball’ idiosyncrasy of the primary characters.
[Aus]J. Byrell Lairs, Urgers & Coat-Tuggers 173: After all that wackiness the prince [...] went and also gave poor old Sirajirao the sandshoe in favour of another of his posho conveyances .
Game Axis Unwired Mag. Dec. 49: All kinds of whackiness ensue here with Logan and Jean Grey being together.
[SA]Mail & Guardian (Johannesburg) 27 May 🌐 [headling] Whacking with wackiness.

In compounds

whacky baccy (n.) (also wacky baccy, …backy, …tabbaccy, ...weed, whackatabacky, whackey tobackey, whacky weed) [whacky adj. + abbr. SE tobacco/weed n.1 (1d)]

(drugs) marijuana; also attrib.

[US]L. Dills CB Slanguage 120: Whackey Tobackey: marijuana.
[US]D. Woodrell Muscle for the Wing 30: Wanda took a Baggie of home grown wacky-backy from the vegetable crisper.
[US]Bentley & Corbett Prison Sl. 71: Wacky Backy A term used to indicate marijuana. It is primarily used by the country ’n’ western or cowboy population of the prison.
[Scot]I. Welsh ‘A Smart Cunt’ in Acid House 195: You’re as high as a bloody kite, son. What are you on? [...] that whacky baccy?
[US]N. McCall Makes Me Wanna Holler (1995) 270: That one rated right up there with acid and wacky weed.
[Aus]Bug (Aus.) 16 Aug. 🌐 I’ve watched you play and trust me, lad, you don’t need wacky tabbaccy.
[UK]Indep. Rev. 1 Dec. 4: The late Beatle once befriended a monkey [...] and shared the fumes of his ‘wacky-baccy’ with it.
[UK]K. Waterhouse Soho 51: Not that Alex had ever done drugs, apart from Es or disco biscuits as they were known, and the odd puff of wacky baccy.
[US]ONDCP Street Terms 22: Wacky weed — Marijuana. [Ibid.] Whackatabacky — Marijuana.
[Aus]S. Maloney Something Fishy (2006) 222: I could see the whacky-backy patch.
[SA]Big Issue (Cape Town) 10 Jan. 20/3: People have been smoking the whacky weed for centuries.
[Scot](con. 1980s) I. Welsh Skagboys 71: One young cop [...] asks us if I’ve been smoking ’waccy baccy’.
[Scot]A. Parks To Die in June 185: ‘Fuck you on about, McCoy? Been smoking the wacky baccy’.
[US]D. Swierczynski California Bear 13: ‘Middle-aged guys like you and me, we’re perfect for the wacky weed’.
whacky dust (n.) [dust n. (5b)]

(US drugs) cocaine.

[US]Chuck Webb ‘Wacky Dust’ 🎵 They call it wacky dust / It’s from a hot cornet, / It gives your feet a feeling so breezy / And oh, it’s so easy to get.

In phrases

do the whacky (v.) [coined in late 1990s US TV show Buffy the Vampire Slayer]

to lose emotional control.

‘Some Assembly Required’ in 22 Sept. ep. of Buffy the Vampire Slayer [TV script] Love makes you do the wacky.
[US]USA Today 23 Dec. 04D: Adams started watching the show two years ago, after hearing Buffy (Sarah Michelle Gellar) say, ‘Love makes you do the wacky’ while he was channel-flipping.
whacky for (adj.)

(US) keen on, fascinated by.

[US]M. Braly On the Yard (2002) 51: Hello, Janice Lee. Are you still whacky for khaki?