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stock, in botany

(Encyclopedia)stock, in botany, common name for any species of the genus Matthiola, for Malcomia maritima (Virginia stock), and for the wallflower, all belonging to the family Cruciferae (or Brassicaceae; mustard f...

farming, in taxation

(Encyclopedia)farming, in the history of taxation, collection of taxes through private contractors. Usually, the tax farmer paid a lump sum to the public treasury; the difference between that sum and the sum actual...

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...

valence, in chemistry

(Encyclopedia)valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound. Atoms are c...

mule, in zoology

(Encyclopedia)mule, hybrid offspring of a male donkey (see ass) and a female horse, bred as a work animal. The name is also sometimes applied to the hinny, the offspring of a male horse and female donkey; hinnies a...

brown dwarf

(Encyclopedia)brown dwarf, in astronomy, celestial body that is larger than a planet but does not have sufficient mass to convert hydrogen into helium via nuclear fusion as stars do. Also called “failed stars,”...

sin, in religion

(Encyclopedia)sin, in religion, unethical act. The term implies disobedience to a personal God, as in Judaism, Christianity, and Islam, and is not used so often in systems such as Buddhism where there is no persona...

depression, in psychiatry

(Encyclopedia)depression, in psychiatry, a symptom of mood disorder characterized by intense feelings of loss, sadness, hopelessness, failure, and rejection. The two major types of mood disorder are unipolar disord...

crane, in zoology

(Encyclopedia)crane, large wading bird found in marshes in the Northern Hemisphere and in Africa. Although sometimes confused with herons, cranes are more closely related to rails and limpkins. Cranes are known for...

in vitro fertilization

(Encyclopedia)in vitro fertilization vēˈtrō, vĭˈtrō [key] (IVF), technique for conception of a human embryo outside the mother's body. Several ova, or eggs, are removed from the mother's body and placed in sp...