Insane (3)

I think it could be either:

Which length description are you looking for?:

mad

'insane' is the definition.
(I know that insane can be written as mad)

This is all the clue.

(Other definitions for mad that I've seen before include "lunatic" , "Crazed" , "Demented or excited or angry" , "Angry or insane" , "Berserk" .)

I've seen this clue in The Mirror, the Evening Standard, The Independent and The Telegraph.

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