Stupid kids hid notice: Avoid all edges (7)

I believe the answer is:

idiotic

I'm a little stuck... Click here to teach me more about this clue!

'stupid' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for idiotic that I've seen before include "Half witted" , "Silly" , "Witless" , "Mindless" , "Absurd, crackbrained" .)

I've seen this clue in The Telegraph.

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