Hi - just to confuse matters further, when I look in the Oxford dictionary errant seems to be the correct answer, yet Chambers indicates arrant as being more likely (grr). I'm swithering...
Hi atsgran after much faffing around I've decided to go with errant (I should have listened to axman in the first place!). Sorry for confusing you. Glad to see the back of this crossword - I thought it was quite tricky this week. Regards, Judy