noun ·3 syllables ·Rare ·Advanced level

Definitions

Noun

1. 1
   An extremely hard mineral, a form of aluminum oxide with the chemical formula Al₂O₃, that occurs in the form of the gemstones sapphire and ruby; it is used as an abrasive. countable, uncountable
2. 2
   very hard mineral used as an abrasive wordnet

Synonyms

All synonyms

abrasivealabasterasphaltcorundomcorundomemery

Example

More examples

"Sapphire is the blue form of corundum."

Etymology

From Tamil குருந்தம் (kuruntam, “ruby, sapphire”) First attested in the early 18th century.

Related phrases

aluminum oxidechemical formula

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.