in Astronomy, a new primary planet, discovered by Dr Herschell in the year 1781. By most foreign, and even by some British philosophers, it is known by the name of Herschell, in honour of the discoverer. As the other planets are distinguished by marks or characters, the planet Herschell is distinguished by an H, the initial letter of the discoverer's name, and a cross to show that it is a Christian planet. See Astronomy Index.