Corresponds to the anterior. (Costomediastinal) line of pleural reflection. 2. It is deeply notched in the left lung posterior. to 5th costal cartilage by the pericardium costal cartilage by the pericardium. and extends vertically downwards to form. Lingula.
Generally speaking, a principle is a rule, standard, or belief of one kind or another. As an adjective, principal means âmost importantâ, while a principal is â generally speaking â a person who is most important in a particular organization or group.
LINK / CITE ADD TO WORD LIST. noun. The definition of a principle is a basic truth or the source or origin of something or someone. An example of principle is a list of values set by a group of people. 1  the ultimate source, origin, or cause of something. 2  a natural or original tendency, faculty, or endowment.