Scatterbrained? In another case, I could be so described (5)

I believe the answer is:

dotty

'scatterbrained?' is the definition.

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

(Other definitions for dotty that I've seen before include "Silly; crazy" , "Slightly crazy" , "Eccentric, slightly mad" , "Barking" , "Mildly eccentric" .)

I've seen this clue in The Guardian.

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