impervium
/ɪmˈpəːvɪəm/Originally and chiefly Science Fiction
noun
A virtually impenetrable or indestructible substance.
- Frequently (and earliest) in attributive use..
Origin
1930s. From imperv- + -ium.
- Russo-Caucasian
- Russo-Chinese
- Russo-Finnish War
- Russo-French
- Russo-German
- Russo-Japanese
- Russo-Japanese War
- Russomaniac
- Russonorsk
- Russophile
- Russophilia
- Russophobe
- Russophobia
- Russophobic
- Russophobism
- Russophobist
- Russophone
- Russo-Polish
- Russo-Slavonic
- Russo-Turkish
- Russo-Turkish Wars
- russula
- rust
- rustball
- rust belt