causation vs nucleus

causation

noun
  • The act or agency by which an effect is produced. 

  • The act of causing. 

  • Cause and effect, considered as a system. 

nucleus

noun
  • A large membrane-enclosed organelle found in eukaryotic cells which contains genetic material. 

  • The central part of a syllable, most commonly a vowel. 

  • The core, central part of something, around which other elements are assembled. 

  • An initial part or version that will receive additions. 

  • The massive, positively charged central part of an atom, made up of protons and neutrons. 

  • A ganglion, cluster of many neuronal bodies where synapsing occurs. 

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