mental, n. — Green’s Dictionary of Slang

mental n.

[abbr. SE mental case/ability/home]

1. an insane, deranged person, a mental patient.

1913		E. Meynell Life F. Thompson 279: Many a time I’ve asked him to have his bit of lunch with me and the other ‘mental’ — O yes, she’s a mental case, as I may have told you .
1944		P. Kendall Dict. Service Sl. n.p.: a mental ... a psychopathic case.
2001		OnLine Dict. of Playground Sl. 🌐 mental adj. [...] 7) mentalist, a mentler.
2010		IOL News (Western Cape) 22 Mar. 🌐 After Richard Hammond seriously injured himself in a 370 km/h crash, Clarkson [...] asked ‘are you now a mental?’.

2. intelligence; the mind.

1975		E. Torres Carlito’s Way 51: If you ain’t got the mental, there’s always a con to feed you your lines.
1989		Freddie Foxxx ‘Forever’ 🎵 Now my mental is active, so I’m always thinkin.
1998		Gang Starr ‘Robbin Hood Theor’ 🎵 I floss my rhymes like dentals, my mental’s presidential.
2008		Chamillionaire ‘Real Thing’ 🎵 Rappers can’t keep up wit my mental.
2012		Kendrick Lamar ‘Sherane A.K.A Master Splinter’s Daughter’ 🎵 Seventeen, with nothing but pussy stuck on my mental.

3. (Aus.) an emotional outburst, a display of ill temper; see chuck a mental

4. (Irish) a psychiatric institution.

1981		J. Bradner Danny Boy 95: Why you-all don’t send John to de flipping mental?
1994		P. Quigley Borderland 55: Aunt Nell told me that the Gunner had been taken to a place called ‘the Mental’ for treatment.

mentaller (n.)

a lunatic.

2009

T. Black Gutted 1: On the hills at night, you hear screams, you start running [...] Mentallers like me chase the screams.

chuck a mental (v.) (also crack a mental, do a mental)

1. (Aus./N.Z.) to lose one’s temper; to have a fit.

1979		Lette & Carey Puberty Blues 51: ‘What happened?’ ‘He cracked a mental.’.
1983		K. Cue Crooks, Chooks and Bloody Ratbags (1988) 193: Do ya wanna go down to old Doc’s and watch him do a mental?
1986		T. Winton That Eye, The Sky 83: ‘Henry chucked a mental,’ I say [...] ‘It was a fit.’.
1993		T. Winton Lockie Leonard: Scumbuster (1995) 80: The guy chucked a mental.
2002		HBW at www.hbdub.com 🌐 This program has performed an illegal operation, so sod off you bodgie dipstick! Your computer’s in a bit of a brothel, you boofhead. Your about as bright as a two-watt bulb. But don’t chuck a mental at me, mate. Talk to that illywacker Laporte.

2. to have an emotional breakdown.

1997

T. Winton Lockie Leonard, Legend (1998) 179: His mum chucked a mental, you know.