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
shill. 1. a person who poses as a customer in order to decoy others into participating, as at a gambling house. 2. a person whose praises, endorsements, etc., are motivated by self-interest. 3. to work as a shill: to shill for a large casino.oun. 1. shill-a decoy who acts as an enthusiastic customer in order to stimulate the participation of others. decoy, steerer-a beguiler who leads someone into danger (usually as part of a plot).