clustering vs tie-in

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. 

tie-in

noun
  • Something that is related or connected to another thing. 

  • An association or connection between things. 

  • An authorized product based on a media property, such as a film or video game, by way of cross-promotion. 

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