extra vs principal

extra

noun
  • A supernumerary or walk-on in a film or play. 

  • A run scored without the ball having hit the striker's bat - a wide, bye, leg bye or no ball. 

  • An extra edition of a newspaper, which is printed outside of the normal printing cycle, for example to report an important late-breaking event. 

  • The state or trait of being over the top, of behaving in an overly dramatic manner. 

  • Something additional, such as an item above and beyond the ordinary school curriculum, or added to the usual charge on a bill. 

  • Something of an extra quality or grade. 

det
  • Denotes more. 

adv
  • To an extraordinary degree. 

adj
  • Beyond what is due, usual, expected, or necessary; extraneous; additional; supernumerary. 

  • Over the top; going beyond what is normal or appropriate, often in a dramatic manner. 

principal

noun
  • The primary participant in a crime. 

  • The chief administrator of a school. 

  • A diapason, a type of organ stop on a pipe organ. 

  • The construction that gives shape and strength to a roof, generally a truss of timber or iron; or, loosely, the most important member of a piece of framing. 

  • A dancer at the highest rank within a professional dance company, particularly a ballet company. 

  • The first two long feathers of a hawk's wing. 

  • A security principal. 

  • A legal person that authorizes another (the agent) to act on their behalf; or on whose behalf an agent or gestor in a negotiorum gestio acts. 

  • The chief executive and chief academic officer of a university or college. 

  • The money originally invested or loaned, on which basis interest and returns are calculated. 

  • A partner or owner of a business. 

  • One of the turrets or pinnacles of waxwork and tapers with which the posts and centre of a funeral hearse were formerly crowned 

adj
  • Chosen or assumed among a branch of possible values of a multi-valued function so that the function is single-valued. 

  • Primary; most important; first level in importance. 

How often have the words extra and principal occurred in a corpus of books? (source: Google Ngram Viewer )