Asterism /(-ĭz'm)/

As·ter·ism

Asterism

n.
  1. A constellation. (Astron.) [Obs.]
  2. An asterisk, or mark of reference. (Printing) [R.]
  3. An optical property of some crystals which exhibit a star-shaped by reflected light, as star sapphire, or by transmitted light, as some mica. (Crystallog.)