dead center vs medial

dead center

noun
  • The exact center. 

  • Synonym of dead point: the position at which a crank is in a direct line with a connecting rod. 

  • A nonrevolving center in a lathe. 

medial

noun
  • Any of various things that occur in the middle. 

  • One or more letters that occur in the middle of a word. 

adj
  • Of or pertaining to the media and/or the areas of the wing next to it. 

  • Pertaining to the inside; closer to the median plane of the body or the midline of an organ. 

  • (of a speech sound) In the middle of a word. 

  • Closer to the addressee. 

  • Of or pertaining to a mean or average. 

  • Pertaining to the middle layer of a blood vessel, to its tunica media. 

  • (of a consonant) Central: produced when air flows across the center of the mouth over the tongue. 

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