Green’s Dictionary of Slang

scooby-doo n.2

[rhy. sl.; ult. TV cartoon character Scooby-Doo]

1. (UK prison) a warder [ = screw n.1 (2c)].

R. Puxley FreshRabbit.

2. (also scooby) a clue.

[UK]J.J. Connolly Layer Cake 270: For about five minutes after, nobody’s gonna have a scooby-doo what’s goin on.
[UK]K. Sampson Outlaws (ms.) 110: I haven’t got a fucking scooby what I’m talking about here.
[US]Eble Campus Sl. Nov.
[Scot](con. 1980s) I. Welsh Skagboys 21: Ah huvnae goat a fuckin scooby what ah’m daein here.
[Scot]I. Welsh Decent Ride 32: I thought you didn’t know who I was! [...] Hudnae a Scobby till ah googled ye.
[Aus]N. Cummins Tales of the Honey Badger [ebook] Personally, I didn’t have a Scooby Doo what everyone was laughing at.

3. (Scots teen) a Subaru automobile.

[Scot]L. McIlvanney All the Colours 83: ‘Scooby [...] Nice ride. Is it turbo, mister?’.
[Scot]G. Armstrong Young Team 127: The Scooby flashes its lights.