Err (5)

I think it could be either:

Which length description are you looking for?:

2,6

stray

'err' is the definition.
(I know that err can be written as stray)

This is all the clue.

(Other definitions for stray that I've seen before include "digress" , "Homeless cat" , "Lost pet" , "Go off course" , "out of place" .)

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

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