fundamental vs simplex

fundamental

noun
  • The lowest partial of a complex tone. 

  • The lowest frequency of a periodic waveform. 

  • A main or major principle, rule, law, etc. which serves as the foundation or basis of a system; an essential part 

adj
  • Related to a foundation. base, or basis; serving as a foundation. 

  • essential; extremely important 

simplex

noun
  • A monomorphemic word, one without affixes. 

  • An analogue in a space of arbitrary dimensionality of the triangle or tetrahedron; the convex hull of n+1 linearly independent points in n-dimensional space; in other words, the triangle, tetrahedron etc., generalized to an arbitrary number of dimensions. 

adj
  • Single, simple; not complex. 

  • Unidirectional. 

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