Meanings
- dateduncountableThe systematic element name for the chemical element with atomic number 118 (symbol Uuo); now named oganesson.
Prior to and during the naming process, the element may be referred to by its atomic number, for example as in ‘element 118’, or by its provisional systematic name, ‘ununoctium’.
2016 March 1, Willem H. Koppenol, John Corish, Javier García-Martínez, Juris Meija and Jan Reedijk, “How to name new chemical elements (IUPAC Recommendations 2016)”, in Pure and Applied Chemistry, volume 88, number 4, →DOI, archived from the original on 11 Nov 2025, page 4041 more example
“The chemistry community is eager to see its most cherished table finally being completed down to the seventh row. IUPAC has now initiated the process of formalizing names and symbols for these elements temporarily named as ununtrium, (Uut or element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118)” said Professor Jan Reedijk, President of the Inorganic Chemistry Division of IUPAC.
2015 December 30, “Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117 and 118”, in IUPAC
Synonyms & antonyms
nounThe systematic element name for the chemical element with atomic number 118 (symbol Uuo); now named oganesson.
Origin
Systematic element name, from un- + un- + oct- + -ium.
Full word history & related roots →Translations
Arabic أُنُون أُوكْتِيُوم
- أُنُون أُوكْتِيُوم (ʔunun ʔuktiyum)chemical element
Catalan ununocti
- ununoctichemical element
Dutch ununoctium
- ununoctiumchemical element
Esperanto ununoktio
- ununoktiochemical element
Estonian ununoktium
- ununoktiumchemical element
Finnish ununoktium
- ununoktiumchemical element
French ununoctium
- ununoctiumchemical element
German Ununoctium
- Ununoctiumchemical element
Greek ουνουνόκτιο
- ουνουνόκτιο (ounounóktio)chemical element
Hungarian ununoktium
- ununoktiumchemical element
Italian ununoctio
- ununoctiochemical element
Korean 우누녹튬
- 우누녹튬 (ununoktyum)chemical element
Malay ununoktium
- ununoktiumchemical element
Norwegian ununoctium
- ununoctiumchemical element
Polish ununoctium
- ununoctiumchemical element
Portuguese ununóctio
- ununóctiochemical element
Romanian ununoctiu
- ununoctiuchemical element
Russian унуно́ктий
- унуно́ктий (ununóktij)chemical element
Spanish ununoctio
- ununoctiochemical element
Swedish ununoktium
- ununoktiumchemical element
Thai อูนอูนออกเทียม
- อูนอูนออกเทียม (ūnūnòktiam)chemical element
Ukrainian унуно́ктій
- унуно́ктій (ununóktij)chemical element
Cite this entry
ununoctium. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/ununoctium
“ununoctium.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ununoctium. Accessed November 4, 2026.
WatkinsX Dictionary, s.v. “ununoctium,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/ununoctium.
Source: ununoctium on Wiktionary, CC BY-SA 4.0.