thorium

Fetched 2026-10-26 (cache).

Synonyms: thorinum

Antonyms: thorinum

Related words from Datamuse; suggestions, not definitions.

Noun

1. {{senseid|en|Q1115}}{{lb|en|chemistry}} A chemical element (symbol {{l|mul|Th}}) with [[atomic number]] 90. A weakly [[radioactive]], [[malleable]], moderately hard silvery [[metal]] that [[tarnish]]es black when exposed to air.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.