instability vs parity

instability

noun
  • The quality of being unstable. 

  • A state that is not in equilibrium, or in which a small change has a large irreversible effect. 

parity

noun
  • A set with the property of having all of its elements belonging to one of two disjoint subsets, especially a set of integers split in subsets of even and odd elements. 

  • The number of delivered pregnancies reaching viable gestational age, usually between 20-28 weeks 

  • The number of times a sow has farrowed. 

  • Symmetry of interactions under spatial inversion. 

  • In reversi, the last move within a given sector of the board. 

  • The classification of an element of a set with parity into one of the two sets. 

  • Equality; comparability of strength or intensity. 

  • The count of one bits in a value, reduced to even or odd or zero or one. 

  • Resemblance; analogy. 

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