from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Lava that forms from an underwater eruption and is characterized by pillow-shaped masses.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The rock type, resembling pillows, typically formed when lava emerges from an underwater volcanic vent or a lava flow enters the ocean.
- n. A rock of that type.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. lava that hardened in rounded shapes suggestive of pillows; believed to result from underwater eruptions
Sorry, no etymologies found.