1. : a plane through a crystal that divides the crystal into two parts that are mirror images of each other
2. : a vertical fore-and-aft plane that divides an airplane into symmetrical halves
1. : a plane through a crystal that divides the crystal into two parts that are mirror images of each other
2. : a vertical fore-and-aft plane that divides an airplane into symmetrical halves
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012