- former name of roentgenium. Symbol: Uuu
Also called element 111.
[rent-gen-ee-uh m, -jen-, ruhnt-]
- a superheavy, synthetic radioactive element with a very short half-life. Symbol: Rg; atomic number: 111.
Origin of roentgenium
Formerly unununium, element 111.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018