Green’s Dictionary of Slang

spangle n.3

[ety. unknown]

(Scot. juv.) a fool.

OnLine Dict. of Playground Sl. 🌐 Spangle n. (1) a very stupid person, i.e. ‘You’re a right spangle!’.

In derivatives

spangled (adj.)

(Scot.) stupid; comatose as a result of consuming drink and/or drugs.

[Scot](con. 1980s) I. Welsh Skagboys 83: Thank fuck they two creepy fuckers ower by are spangled; Sergeant Salt n pepper’s nearly asleep. The dwarfish fucker’s heid lollin.
[Scot]I. Welsh Dead Man’s Trousers [13]: Boy’s spangled now, just aboot able tae show a slab ay fear .
[Scot]A. Parks April Dead 100: [S]o spangled he could hardly stand.