Dictionary.com
Thesaurus.com

hydrargillite

American  
[hahy-drahr-juh-lahyt] / haɪˈdrɑr dʒəˌlaɪt /

noun

Mineralogy.
  1. gibbsite.


Etymology

Origin of hydrargillite

First recorded in 1795–1805; hydr- 1 + argillite