longitudinal vs proportional

longitudinal

adj
  • Relating to length, or to longitude. 

  • Running in the direction of the long axis of a body. 

  • Forward and/or backward, relative to some defined direction. 

  • Sampling data over time rather than merely once. 

noun
  • Any longitudinal piece, as in shipbuilding etc. 

  • A railway sleeper lying parallel with the rail. 

proportional

adj
  • At a constant ratio (to). Two magnitudes (numbers) are said to be proportional if the second varies in a direct relation arithmetically to the first. Symbol: ∝. 

  • In proportion (to), proportionate. 

  • Of a typeface, having characters with natural (non-uniform) width (in contrast to monospace typefaces). 

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