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
Babel(Noun) A confused mixture of sounds and voices, especially in different languages. Babel(Noun) A place or scene of noise and confusion. Babel(Noun) A tall, looming structure. Babel(ProperNoun) The city and tower in the land of Shinar where the confusion of languages took place, according to the Bible.