Green’s Dictionary of Slang

one tablet or capsule of LSD.

1970		Esquire 73 181/3: As they pulled out of the parking lot, she popped an acid cap.
2002		DRUG-ARM Aus. 🌐 Slang Terms: acid cap – LSD.

1. one whose brain is deemed to have suffered from an excess of hallucinogens.

1971		‘Captain Beefheart’ (Don van Vliet) in Changes mag. n.p.: Do I think I’m an acid-casualty or something like they talk about, I think not.
1989		Spin Mar. 25/2: ‘I think that I'm very, very sane,’ says Julian [Cope], long labeled a hopeless acid casualty, really off his box.
1997		Daily Vault 10 Mar. n.p.: The only album to be released featuring early rock acid casualty Syd Barrett on lead vocals and guitar, this album defies logic and the senses – in fact, take the whole rule book of rock and throw it out the window.
2002		h2g2 🌐 If one frequently takes large doses of LSD – perhaps 12 blotters – one will become what is known as an ‘acid casualty’. This is someone who, possibly only temporarily, shows all the signs of taking too much LSD. Acid casualties have been known to recover.

2. the victim of an excess of MDMA.

2002

zeitgeistfilms.com 🌐 Perhaps best known for his film role as the speeding Spud in ‘Trainspotting’, Bremner first appeared in the stage version of ‘Trainspotting’ as Renton. He stars in THE ACID HOUSE as the acid casualty Coco Bryce.

the recurrence of an LSD trip at some unspecified later date; the experience is assumed to be unpleasant.

1969		NY Workshop in Nonviolence Win Peace & Freedom 32/1: A friend was busted for grass in Japan and took that opportunity to claim that he had an acid flashback [...] he was sent to the nearest psychiatrist at once.
1976		International Journal of the Addictions XI:1–3 65: The best single predictor of acid flashback occurrence was marijuana use.
1987		L.A. Due Give Me Time 275: She told herself she was hallucinating, having an acid flashback without ever dropping acid.
1999		M. Dery Pyrotechnic Insanitarium 151: Marilyn Manson’s video The Beautiful People subjected the MTV audience to a bad-acid flashback of weirdos in leg braces, a fat man in bondage [etc.].
2007		S. Maconie Pies and Prejudice (2008) 1: It’s like a coach driver’s acid flashback, lurid and random.
2011		D.D. Brazill ‘Lady and the Gimp’ in Pulp Ink [ebook] Abbott’s frankly barmy sermons were as famous as his acid flashbacks.

(drugs) a regular user of LSD.

1967		S. Holt Sex & Teen-age Revolution 74: John, twenty, who calls himself an ‘acid freak,’ seems always bright and happy, perhaps constantly ‘turned on.’ He [...] loves love and loves sex, and that LSD makes it all more exciting.
1969		R.R. Lingeman Drugs from A to Z (1970) 25: acid freak [...] (1) a user of LSD-25. (2) one who exhibits the dress, behaviour patterns, etc., of the LSD cult and whose behaviour is bizarre.
1972		J. Wambaugh Blue Knight 293: What’ve you got, boy? Bennies or reds? Or maybe you’re an acid freak?
1981		D.E. Miller Bk of Jargon 339: acid freak One who habitually uses LSD and exhibits bizarre behaviors resulting from its use.
1994		T. Willocks Green River Rising 69: A mixed bag of […] Angels, acid freaks and punks.
2001		ONDCP Street Terms 1: Acid freak — Heavy user of LSD.

1. a regular user of LSD.

1965		P. Wylie Esquire July 44–45: acid head — LSD user.
1971		J. Simon Sign of Fool 64: Frank was rapping shit [...] trying to convince everyone that the two ‘acid heads’ were a couple of lunatics.
1982		J. Sullivan ‘The Yellow Peril’ Only Fools and Horses [TV script] D’you realise our mum’s grave is now going to become a beacon for every Satanist and acid-head in England.
1986		J. Ellroy Suicide Hill 8: Jesus shriekers and mind-blown acidhead mystics awaiting lunacy hearings.
1999		Guardian Media 2 Aug. 3: The people doing this research were not acid heads, but they considered LSD to be one of the tools for experiment.
2001		ONDCP Street Terms 1: Acid head — User of LSD.
2010		K. Richards Life 207: A couple of flying acid-heads who’d been up for a couple of nights.

2. attrib. use of sense 1.

1967		J. Rechy Numbers (1968) 203: Donovan slurring acid-head images about Superman, Green Lantern, and a velvet theme.
2000		W.T. Vollmann Royal Family 634: Old acidhead Californians.

an illegal party, often held in a large building, such as a warehouse, usu. just outside a major city, where thousands of young people pay for entrance, dance to house music and, allegedly, consume MDMA and other illegal drugs.

1988		Indep. 7 Nov. 2/4: Police fear Acid House parties [...] provide an ideal opportunity for professional criminals to sell drugs, particularly the ‘designer’ drug Ecstasy favoured in the Acid House culture.
1991		D. Jarman letter Smiling in Slow Motion (2000) 48: Later we went to Derek Ball’s, who threw an acid-house party for a group of tipsy boys from Brighton.

(US drugs) a place where LSD is consumed.

1986		Chapman NDAS 2: acid pad n phr narcotics A place, esp someone’s home or apartment, where LSD is taken.
2002		I. Israely America Sl. Dict. 🌐 English-Hebrew acid pad.

(drugs) one who takes extra-large doses of LSD.

1968

T. Wolfe Electric Kool-Aid Acid Test (1969) 194: Acid rappers, freaks who made a competition out of who could take the most acid — they all seemed to end up loose in the head.

a musical style allegedly influenced by, and purporting to recreate the sensations of, LSD and similar psychedelics; orig. in 1960s but underwent a minor revival in 1980s.

1966		Life 9 Sept. 68/3: But true ‘acid rock’ goes deeper psychedelically than just lyrics. It employs a monotonous, harshly amplified drone sound which can act as a psychedelic stimulus.
1968		T. Wolfe Electric Kool-Aid Acid Test (1969) 212: Through the [Grateful] Dead’s experience with the Pranksters was born the sound known as ‘acid rock’.
1970		Time 12 Jan. 38: College kids who have grown tired of the predictable blast-furnace intensity of acid-rock.
1994		Rebennack & Rummel Under A Hoodoo Moon 129: This marked the beginning of a whole mess of ‘acid rock’ sessions.
2000		Guardian Rev. 12 May 6: A strong cultural link with progressive politics, acid rock and groovy domestic arrangements – in short, with the Revolution, man.

a party.

1968		T. Wolfe Electric Kool-Aid Acid Test (1969) 278: Mostly I’d call the Acid Test a master production. Everything was very carefully meshed and calculated to produce the LSD effect.
1969		R.R. Lingeman Drugs from A to Z (1970) 26: acid test [...] Party at which guests wear bizarre, colourful costumes and clown make-up and dance randomly to the accompaniment of raga music or acid rock, while slides and stroboscopic lights are flashed on the walls, the intention being to mimic and/or enhance the LSD experience. [...] A punch containing LSD, called electric kool-ade, is often served.

1. the experience, often characterized as a ‘journey’, of taking a hallucinogenic drug, esp. LSD.

1964		Mother Nov./Dec. 64: We are supposed to go on an acid trip tonight.
1968		Atlantic Monthly Dec. 146: He sometimes receives telephone calls from kids on bad acid trips thinking of suicide.
1976		N. Thornburg Cutter and Bone (2001) 20: They think their poor dear Maureen took one acid trip too many.
1980		E. Folb Runnin’ Down Some Lines 174: I’ve taken one acid trip, you know, to see what it was like, but I didn’t like it.
1995		Recreational Drug Information Website 🌐 I’ve candyflipped once, and it was an incredible experience. The X gives its warm, loving glow to the acid trip and actually potentiates it a bit.
2000		Indep. Rev. 7 Apr. 13: Tellytubbies is really a funky acid trip for warped playschool kids.
2003		G. Tate Midnight Lightning 3: Aliens from a planet with a purple hazy atmosphere, not an acid trip.
2023		F. Bill Back to the Dirt 121: ‘Your acid trip, takes about forty-five minutes to an hour’.

2. a dose of LSD.

1979		Lette & Carey Puberty Blues 113: Their mother’s Mandrax, Valium or an acid trip at four dollars a pill.
2000		J.J. Connolly Layer Cake 117: Acid trips. He makes them. He’s a chemist for us.

(W.I.) to drink rum.

1970		F. Collymore Notes for Gloss. of Barbadian Dial. 49: Fire (sl.) ‘Come lewwe fire one’ is a common invitation to have a drink, generally rum. See fire the acid.
1996		Allsopp Dict. Carib. Eng. Usage 9/1: acid. n. (Bdos, Guyn) [AF] [...] fire the acid [AF] to drink rum.

(drugs) phencyclidine.

1979		H. Feldman et al. Angel Dust 124: The large number of street names it has been accorded over the years: [...] new acid.
2001		ONDCP Street Terms 15: New acid — PCP.

(drugs) LSD, esp. when dropped onto a square of blotting-paper, or when combined with another drug.

1977		L. Young et al. Recreational Drugs.
1981		D.E. Miller Bk of Jargon 338: paper acid: LSD (blotter acid).
2001		ONDCP Street Terms 16: Paper acid — LSD.

(drugs) ketamine.

2001

ONDCP Street Terms 20: Super acid — Ketamine.