clustering vs combination

clustering

noun
  • A grouping of a number of similar things. 

  • The undesirable contiguous grouping of elements in a hash table. 

  • A prewriting technique consisting of writing ideas down on a sheet of paper around a central idea within a circle, with the related ideas radially joined to the circle using rays. 

  • The grouping of a population based on ethnicity, economics or religion. 

adj
  • Forming a cluster. 

combination

noun
  • An object formed by combining. 

  • One or more elements selected from a set without regard to the order of selection. 

  • An association or alliance of people for some common purpose. 

  • A combination shot; a billiard; a shot where the cue ball hits a ball that strikes another ball on the table. 

  • A sequence of numbers or letters used to open a combination lock. 

  • The act of combining, the state of being combined or the result of combining. 

  • A rapid sequence of punches or strikes in boxing or other combat sports. 

  • A motorcycle and sidecar. 

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