knock on wood vs predicate

knock on wood

verb
  • To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement. 

intj
  • Hopefully; a self-directive to undertake the customary action to ward off bad luck. 

predicate

verb
  • To assume or suppose; to infer. 

  • To announce, assert, or proclaim publicly. 

  • To assert or state as an attribute or quality of something. 

  • To make a term (or expression) the predicate of a statement. 

  • to base (on); to assert on the grounds of. 

noun
  • A term of a statement, where the statement may be true or false depending on whether the thing referred to by the values of the statement's variables has the property signified by that (predicative) term. 

  • An operator or function that returns either true or false. 

  • The part of the sentence (or clause) which states a property that a subject has or is characterized by. 

adj
  • Predicated, stated. 

  • Relating to or being any of a series of criminal acts upon which prosecution for racketeering may be predicated. 

  • Of or related to the predicate of a sentence or clause. 

How often have the words knock on wood and predicate occurred in a corpus of books? (source: Google Ngram Viewer )