# ruthenium

> English word · Noun · IPA /ɹuːˈθiːniəm/ · frequency rank #79,030

## Definitions
1. A metallic chemical element (symbol Ru) with an atomic number of 44.
2. An atom of this element.

## Etymology
Ruthenia + -ium. Named by Baltic German scientist Karl Ernst Claus in 1844 in honour of Russia (using the Latin name Ruthenia).

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/ruthenium