In appearance, this does point to an iris identification, but we cannot give you an accurate id this from this tuber. We'd recommend that you keep it in a cool, not too dry area this winter, and pot it up next spring. See what it produces. Then you can send us photos of the leaves and possibly flowers for id, or you may be able to id it yourself by then. Do not put it in the ground and allow it to spread until you know what you've got.