OBSIDIAN

Pronunciation (US):

(GB):

 I. (noun) 

Sense 1

Meaning:

Acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces

Classified under:

Nouns denoting substances

Hypernyms ("obsidian" is a kind of...):

volcanic glass (a kind of natural glass produced when molten lava cools very rapidly)

Credits