noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A metallic chemical element (symbol Pm) with an atomic number of 61. uncountable
2. 2
   a soft silvery metallic element of the rare earth group having no stable isotope; was discovered in radioactive form as a fission product of uranium wordnet

Synonyms

All synonyms

atomic number 61cycloniumelementflorentiumflorentiumgold

Etymology

1945. From the name of the Greek god Prometheus, who stole the fire from Mount Olympus and brought it down to mankind + -ium.

Related phrases

promethium chloridepromethium nitrateatomic number

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.