Druse (Druzes) Members of a Middle Eastern religious sect. A breakaway group of the Ismailis, the Druse originated in the reign of al-Hakim (996–1021), sixth Fatimid caliph of Egypt, who claimed to be divine. They are named after al-Darazi, the first to proclaim the cult publicly. Stressing pure monotheism, they emphasize the possibility of direct communication with divinity as a living presence. They were persecuted in Egypt, fought against both Turks and local Christians, and against French rule in Syria in the 1920s. There are about 500,000 Druses living in Syria, Lebanon, and Israel.

druse (adj. drusy) A cavity (vugh) in an igneous rock or a mineral vein into which euhedral (well-formed) crystals of the rock or mineral vein project, or the crystals themselves. The cavity represents a volume of late-stage, vapour-rich magma trapped by the rock crystallizing around it. Crystals can grow freely into this medium and hence crystallize in perfect forms (e.g. smokey quartz in granite) to give well-shaped crystal faces. The word is German, Druse meaning decayed or weathered ore.

druse / droōz/ • n. 1. Geol. a rock cavity lined with a crust of projecting crystals. ∎  the crust of crystals lining such a cavity.2. Bot. a rounded cluster of calcium oxalate crystals found in some plant cells.DERIVATIVES: drus·y adj. ( Geol. ).

druse (sphaeroraphide) A spiky, globular mass of crystals, usually of calcium oxalate, formed around a centre of organic material and found free inside cells or attached to cell walls in cortex, pith, and phloem tissue.

druse crystals lining a rock-cavity. XIX. — F. — G. druse weathered ore = MLG. drūse, drōse, Du. droes.