Main Entry:

ad·a·man·tine

Pronunciation:

\ˌa-də-ˈman-ˌtēn, -ˌtīn, -ˈman-t^ən\

Function:

adjective

Etymology:

Middle English, from Latin adamantinus, from Greek adamantinos, from adamant-, adamas

Date:

13th century

1 : made of or having the quality of adamant 2 : rigidly firm : unyielding <adamantine discipline> 3 : resembling the diamond in hardness or luster