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
Noun[edit] muffle â(plural muffles) 1  Anything that mutes or deadens sound. 2  A warm piece of clothing for the hands. 3  A kiln or furnace, often electric, with no direct flames (a muffle furnace)  The bare end of the nose between the nostrils, especially in ruminants.