When a geometry is described by a set of axioms, the notion of a line is usually left undefined (a so-called primitive object). The properties of lines are then determined by the axioms which refer to them.
Definition of mull 1: friable forest humus that forms a layer of mixed organic matter and mineral soil and merges gradually into the mineral soil beneath 2: a finely powdered solid especially in a suspension
Definition of MULLEIN. : any of a genus (Verbascum) of usually woolly-leaved Eurasian herbs of the snapdragon family including some that are naturalized in North America.See mullein defined for kids.efinition of MULLEIN. : any of a genus (Verbascum) of usually woolly-leaved Eurasian herbs of the snapdragon family including some that are naturalized in North America. See mullein defined for kids.