Green’s Dictionary of Slang

1. (UK/US prison) a prisoner whose confinement has driven him mad.

1936		San Quentin Bulletin in L.A. Times 6 May 7: DINGALINGS, goofy prisoners, or those called ‘stir simple’ after long years in prison.
1950		Goldin et al. DAUL 58/2: Dingaling. (Pacific Coast prisons) A convict softened mentally by imprisonment.
1976		M. Braly False Starts 52: Of the four of us I was the most marginal, most rumlike, closest in style to the dingalings and fruiters who marched alone in O Company.
1992		Bentley & Corbett Prison Sl. 29: Stir Crazy Some men who come to prison cannot mentally adjust to the many hours of continuous confinement in their cells. [...] (Archaic: stir-bug, dingaling).

2. (US) a fool, an eccentric, a mad person.

[1933		Hollywood Herald 24 Aug. 9/1: Know what a Ding-a-Ling is? It’s a person who hears something confidentially and breaks a femur dashing to a telephone to tell it to a third person].
1944		O. Ferguson ‘Vocabulary for Lakes, [etc.]’ AS XIX:2 104: A man who acts up partly through liquor and partly through something defective in his parents is [...] some kind of ding-a-ling.
1960, 1975		Wentworth & Flexner DAS.
1967		New Yorker 27 May 33: Always wearing black tights under her dress and other kinds of kinky gear [...] This kid is a dangerous ding-a-ling and I don’t know why I handle her.
1975		J. Wambaugh Choirboys (1976) 42: She’s a dingaling, and there’s ways to handle them.
1989		(con. 1960) P. Theroux My Secret Hist. (1990) 96: Then he knifed her. She didn’t press charges. What a ding-a-ling!
1998		J. Lansdale Rumble Tumble 126: We got just as good a chance finding the place doing that as fuckin’ around with this ding-a-ling.