copula vs nexus

copula

noun
  • A word, usually a verb, used to link the subject of a sentence with a predicate (usually a subject complement or an adverbial), that unites or associates the subject with the predicate. 

  • A device that connects two or more keyboards of an organ. 

  • A function that represents the association between two or more variables, independent of the individual marginal distributions of the variables. 

  • The act of copulation; mating. 

nexus

noun
  • A form or state of connection. 

  • A centre or focus of something. 

  • A person who had contracted a nexum or obligation of such a kind that, if they failed to pay, their creditor could compel them to work as a servant until the debt was paid; an indentured servant. 

  • The relationship between a vendor and a jurisdiction for the purpose of taxation, established for example by the vendor operating a physical store in that jurisdiction. 

  • A connected group; a network, a web. 

  • In the work of the Danish linguist Otto Jespersen (1860–1943): a group of words expressing two concepts in one unit (such as a clause or sentence). 

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