| formation | 1. The act of giving form or shape to anything; a forming; a shaping. 2. The manner in which a thing is formed; structure; construction; conformation; form; as, the peculiar formation of the heart. 3. A substance formed or deposited. 4. <geology> Mineral deposits and rock masses designated with reference to their origin; as, the siliceous formation about geysers; alluvial formations; marine formations. A group of beds of the same age or period; as, the Eocene formation. 5. The arrangement of a body of troops, as in a square, column, etc. Origin: L. Formatio: cf. F. Formation. Source: Websters Dictionary (01 Mar 1998) |
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| leukodystrophy with diffuse Rosenthal fibre formation | A metabolic disorder whose onset can be in infancy, adolescence, or adulthood; characterised pathologically by widespread cerebral demyelination with astrocyte and primitive oligodendroglial cell proliferation; refractile Rosenthal fibres result from the degeneration of these proliferating cells; aetiology unknown, but possibly due to a metabolic defect of astrocytes; sex-linked recessive disorder. (05 Mar 2000) |