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 Evening Standard, The Telegraph and The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.