| primordial | 1. First in order; primary; original; of earliest origin; as, primordial condition. "The primordial facts of our intelligent nature." 2. <geology> Of or pertaining to the lowest beds of the Silurian age, corresponding to the Acadian and Potsdam periods in American geology. It is called also Cambrian, and by many geologists is separated from the Silurian. 3. <biology> Originally or earliest formed in the growth of an individual or organ; as, a primordial leaf; a primordial cell. <botany> Primordial utricle, the interior lining of a young vegetable cell. Origin: L. Primordialis, from primordium the first beginning; primus first + ordiri to begin a web, to begin: cf. F. Primordial. Source: Websters Dictionary (01 Mar 1998) |
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| primordial cartilage | Cartilage in an early stage in its development. (05 Mar 2000) |
| primordial cell | A cell from a group that constitutes the primordium of an organ or part of the embryo. (05 Mar 2000) |
| primordial cyst | A cyst which develops in place of a tooth through cystic degeneration of the enamel organ prior to formation of calcified odontogenic tissue. (05 Mar 2000) |
| primordial dwarfism | Dwarfism characterised by normal development that is at a strikingly lesser rate than that for members of the same family, race, or other races. Synonym: primordial dwarfism, true dwarfism. (05 Mar 2000) |
| primordial germ cell | The most primitive undifferentiated sex cell, found initially outside the gonad. Synonym: gonocyte. (05 Mar 2000) |
| primordial gigantism | Unusually large size from birth due to familial or genetic factors or intrauterine environment (e.g., maternal prediabetic state) and not to hyperpituitarism. (05 Mar 2000) |
| primordial kidney | 1. The definitive excretory organ of primitive fishes. Synonym: head kidney. 2. In the embryos of higher vertebrates, a vestigial structure consisting of a series of tortuous tubules emptying into the cloaca by way of the primary nephric duct; in the human embryo, the pronephros is a very rudimentary and temporary structure, followed by the mesonephros and still later by the metanephros. Synonym: forekidney, primordial kidney. Origin: pro-+ G. Nephros, kidney (05 Mar 2000) |
| primordial ovarian follicle | A follicle in which the primordial oocyte is surrounded by a single layer of flattened follicular cells. (05 Mar 2000) |