Dictionary.com
definitions
  • synonyms

ununseptium

[uhn-uh n-sep-tee-uh m]
See more synonyms on Thesaurus.com
noun Chemistry, Physics.
  1. a superheavy, synthetic, radioactive element with a short half-life. Symbol: Uus; atomic number: 117.
Also called element 117.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018