druse

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A cavity or opening in rock lined with tiny crystals, usually composed of the same minerals that occur in the rock.

from The Century Dictionary.

• noun A rock-cavity lined with crystals; a geode, or, as miners call it, a vug.
• noun One of a people and religious sect of Syria, living chiefly in the mountain regions of Lebanon and Anti-libanus and the district of Hauran.

from the GNU version of the Collaborative International Dictionary of English.

• noun One of a people and religious sect dwelling chiefly in the Lebanon mountains of Syria.
• noun (Min.) A cavity in a rock, having its interior surface studded with crystals and sometimes filled with water; a geode.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy An inner surface with a crust of tiny crystals.
• noun botany An aggregation of calcium oxalate crystals found in certain plants.
• noun ophthalmology A tiny yellow or white accumulation of extracellular material that builds up in Bruch's membrane of the eye.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an adherent of an esoteric monotheistic religious sect living in the relative security of the mountains of Syria and Lebanon who believes that Al-hakim was an incarnation of God