◎◎◎dead zone⪢⪢
You probably know what a _____ is. It's a place with no cellphone or wireless coverage. But the term isn't in the printed dictionary yet. It probably will be some day soon.
http://qindex.info/i.php?x=14742
○○○classify⪢⪢
Another way topologists classify things are in terms of the number of distinct loops you can draw around the surface of a shape.
http://qindex.info/i.php?x=5172