Individual #historical_linguistics__diachronic_linguistics__comparative_linguistics__comparativelinguistic  the study of linguistic change
  >part of:  linguistics  the scientific study of language
  >part:  etymology.studies  the study of the sources and development of words
  url:  http://en.wikipedia.org/wiki/Historical_linguistics
  part:  sound_law__soundlaw  a law describing sound changes in the history of a language

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