generatrix

from The Collaborative International Dictionary of English v.0.48
Generatrix \Gen`er*a"trix\, n.; pl. L. {Generatrices}, E.
   {Generatrixes}. [L.] (Geom.)
   That which generates; the point, or the mathematical
   magnitude, which, by its motion, generates another magnitude,
   as a line, surface, or solid; -- called also {describent}.
   Generic
    

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