Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


noun di·a·base \ˈdī-ə-ˌbās\

Definition of diabase

  1. 1 archaic :  diorite

  2. 2 chiefly British :  an altered basalt

  3. 3 :  a fine-grained rock of the composition of gabbro but with an ophitic texture


play \ˌdī-ə-ˈbā-sik\ adjective

Origin and Etymology of diabase

French, probably from Greek diabasis act of crossing over, from diabainein to cross over, from dia- + bainein to go — more at come

First Known Use: circa 1816

Learn More about diabase

Seen and Heard

What made you want to look up diabase? Please tell us where you read or heard it (including the quote, if possible).