y is the "ordinate".
See also:
This article (or an earlier version of it) contains material from FOLDOC, used with permission. Modify if needed.
... island of the Russian Federation, being 948 km (589 miles) long, and 25 to 170 km (16 to 105 miles) wide, with an area of 78,000 km² (24,560 sq. miles). The capital of ...