Wandering, having gone off? (12)

I believe the answer is:

sleepwalking

'wandering having gone off?' is the definition.
(wandering when asleep or 'off')

This is the entire clue.

(Other definitions for sleepwalking that I've seen before include "Somnambulance" , "Somnambulism" .)

I've seen this clue in The Telegraph.

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