| n. | 1. | (Chem.) An elementary substance, one of the constituents of didymium; - so called from the green color of its salts. Symbol Ps. Atomic weight 143.6. |
| Noun | 1. | praseodymium - a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process Synonyms: atomic number 59, Pr |