Search Result for "corundum": 
Wordnet 3.0

NOUN (1)

1. very hard mineral used as an abrasive;
[syn: corundom, corundum]

The Collaborative International Dictionary of English v.0.48:

Corundum \Co*run"dum\ (k[-o]*r[u^]n"d[u^]m), n.; pl. Corundums (k[-o]*r[u^]n"d[u^]mz). [Also corindon.] [From Hind. kurand corundum stone.] (Min.) The mineral alumina (Al2O3), as found native in a crystalline state. Transparent varieties are used as gemstones, including sapphire, which is the fine blue variety; the oriental ruby, or red sapphire; the oriental amethyst, or purple sapphire; and adamantine spar, the hair-brown variety. It is the hardest substance found native, next to the diamond. [1913 Webster +PJC] Note: The name corundum is sometimes restricted to the non-transparent or coarser kinds. Emery is a dark-colored granular variety, usually admixed with magnetic iron ore. [1913 Webster]
WordNet (r) 3.0 (2006):

corundum n 1: very hard mineral used as an abrasive [syn: corundom, corundum]