Name for the turning opening I'm translating a set of sewing instructions from German to English. I don't know a lot of sewing vocabulary, and I'm having trouble finding some of it in dictionaries, Wikipedia and so on. The term I'm asking for here is Wendeöffnung - literally "turn opening" - the hole you leave unstitched when sewing something inside-out so that you can turn it right-side-out. What is that usually called in English?
I agree with the comments.  "Leave a gap or space" would work, instead of a trying to use a single specific word.