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boulder, in geology

(Encyclopedia)boulder, large rock fragment formed by detachment from its parent consolidated rock by weathering and erosion. In engineering and geology, especially in the United States, the term is applied to loose...

formula, in chemistry

(Encyclopedia)formula, in chemistry, an expression showing the chemical composition of a compound. Formulas of compounds are used in writing the equations (see chemical equations) that represent chemical reactions....

rust, in botany

(Encyclopedia)rust, in botany, name for various parasitic fungi of the order Uredinales and for the diseases of plants that they cause. Rusts form reddish patches of spores on the host plant. About 7,000 species ar...

chord, in geometry

(Encyclopedia)chord kôrd [key], in geometry, straight line segment both end points of which lie on the circumference of a circle or other curve; it is a segment of a secant. A chord passing through the center of a...

drainage, in mining

(Encyclopedia)drainage, in mining, removal of water seeping into shafts and other underground mine workings from the surrounding ground. Unless seeping water is removed continually, it may endanger haulage and mini...

naturalism, in philosophy

(Encyclopedia)naturalism, in philosophy, a position that attempts to explain all phenomena and account for all values by means of strictly natural (as opposed to supernatural) categories. The particular meaning of ...

nautilus, in zoology

(Encyclopedia)nautilus or chambered nautilus, cephalopod mollusk belonging to the sole surviving genus (Nautilus) of a subclass that flourished 200 million years ago, known as the nautiloids. The spirally coiled sh...

cone, in botany

(Encyclopedia)cone or strobilus strŏbˈələs [key], in botany, reproductive organ of the gymnosperms (the conifers, cycads, and ginkgoes). Like the flower in the angiosperms (flowering plants), the cone is actual...

hyacinth, in botany

(Encyclopedia)hyacinth, any plant of the genus Hyacinthus, bulbous herbs of the family Liliaceae (lily family) native to the Mediterranean region and South Africa. The common, or Dutch, hyacinth of house and garden...

lime, in botany

(Encyclopedia)lime, in botany, small shrublike tree (Citrus aurantifolia) of the family Rutaceae (rue family), one of the citrus fruit trees, similar to the lemon but more spreading and irregular in growth. The tru...