Urman Dictionary

drop portal

noun phrase

A gateway to another dimension that small dropped objects apparently disappear into.

A related phenomenon is the delay portal, a gateway that leads a few minutes into the future. This results in fruitless searching followed by finding the object in an obvious, highly-visible location.

I know I heard my pen hit the floor here, but I can’t find it anywhere. It must have fallen into a drop portal. Oh wait - there it is! I guess it was a delay portal instead.