asterism vs cluster

asterism

noun
  • An unofficial constellation (small group of stars that forms a visible pattern). 

  • A rarely used typographical symbol (⁂, three asterisks arranged in a triangle), used to call attention to a passage or to separate subchapters in a book. 

  • A star-shaped figure exhibited by some crystals by reflected light (as in a star sapphire) or by transmitted light (as in some mica). 

cluster

noun
  • A group of galaxies or stars that appear near each other. 

  • A sequence of two or more words that occur in language with high frequency but are not idiomatic; a chunk, bundle, or lexical bundle. 

  • A small metal design that indicates that a medal has been awarded to the same person before. 

  • A set of bombs or mines released as part of the same blast. 

  • A logical data storage unit containing one or more physical sectors (see block). 

  • An ensemble of bound atoms or molecules, intermediate in size between a molecule and a bulk solid. 

  • A group of computers that work together. 

  • A group or bunch of several discrete items that are close to each other. 

  • A number of individuals grouped together or collected in one place; a crowd; a mob. 

  • A clusterfuck. 

  • A subset of a population whose members are sufficiently similar to each other and distinct from others as to be considered a distinct group; such a grouping in a set of observed data that is statistically significant. 

  • A group of consonants. 

  • A secundal chord of three or more notes. 

verb
  • To cover with clusters. 

  • To collect into clusters. 

  • To form a cluster or group. 

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