A friend and I have recently begun wondering about how to translate a certain term from an English book into Latin. More specifically, it's the word "portkey", created by the author of Harry Potter. In short, a "portkey" is a thing that can be used to instantly transport people from one place to another. However, we find it very difficult to come up with a Latin expression for this, especially because we'd like this Latin expression to be at least a tad catchy. I have a couple of attempts here. Please tell me if they are valid, and do contribute if you have any suggestions.
clavis portandi (key of transporting)
clavis portae (literally port key I guess)
clavis portans (key that transports)
clavis portanda (key that is to be transported)
As you see, it becomes increasingly difficult as the "port" in "portkey" can be regarded as both a verb and a noun.