meridian vs upper limit

meridian

noun
  • A ring or half-ring with markings in which an artificial globe is installed and may spin. 

  • In full celestial meridian: a great circle passing through the poles of the celestial sphere and the zenith for a particular point on the Earth's surface. 

  • A line passing through the poles of any sphere; a notional line on the surface of a curved or round body (in particular, an eyeball). 

  • The highest or most developed point, or most splendid stage, of something; culmination, peak, zenith. 

  • Any of the pathways on the body along which chi or qi (life force) is thought to flow and, therefore, the acupoints are distributed; especially, one of twelve such pathways associated with organs of the body. 

  • Chiefly followed by of: the middle period of someone's life, when they are at their full abilities or strength; one's prime. 

  • In full terrestrial meridian: a great circle on the Earth's surface, passing through the geographic poles (the terrestrial North Pole and South Pole); also, half of such a circle extending from pole to pole, all points of which have the same longitude. 

  • The place on the celestial meridian where it is crossed by the sun or a star at its highest point. 

adj
  • Relating to a meridian (in various senses); meridional. 

  • Relating to midday or noon. 

verb
  • Of a celestial body: to reach its meridian. 

  • To cause an object to reach the meridian or highest point of (something). 

upper limit

noun
  • The upper limit of a sequence of real numbers is the real number which can be found as follows: remove the first term of the sequence in order to obtain the "first subsequence." Then remove the first term of the first subsequence in order to obtain the "second subsequence." Repeat the removal of first terms in order to obtain a "third subsequence," "fourth subsequence," etc. Find the supremum of each of these subsequences, then find the infimum of all of these supremums. This infimum is the upper limit. 

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