How do you spell Pica

Available Definitions:
1)  n. - The genus that includes the magpies.
2)  n. - A vitiated appetite that craves what is unfit for food, as chalk, ashes, coal, etc.; chthonophagia.
3)  n. - A service-book. See Pie .
4)  n. - A size of type next larger than small pica, and smaller than English.