Meaning of didymium

di•dym•i•um

Pronunciation: (dī-dim'ē-um, di-), [key]
— n. Chem.
  1. a mixture of neodymium and praseodymium, formerly thought to be an element. Symbol: Di
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.