pillow lava: Meaning and Definition of

pil'low la"va

Pronunciation: [key]
— Geol. Geol.
  1. lava in the form of an agglomeration of rounded, pillow-shaped masses, the result of subaqueous or subglacial volcanic eruption.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.