noun

• (uncountable, linguistics) The scientific study of the origin and evolution of a word's semantic meaning across time, including its constituent morphemes and phonemes.
  "Holonyms: historical linguistics < linguistics"
• (countable) The entire catalogue of meanings that a word, morpheme, or sign has carried throughout its history.
  "Although written the same, the words lead (the metal) and lead (the verb) have totally different etymologies."
• (countable) An account of the origin and historical development of a word as presented in a dictionary or the like.
  "Etymologies appeal to people with a very wide variety of interests and intellectual backgrounds. A very few people, such as myself, spend most of their time researching etymologies. A slightly larger number do so very occasionally. Many, many more people look at etymologies, but have never researched any themselves. Some people will never even have thought of etymologies as things which need to be researched. Particularly when etymologies are encountered in the compressed form found in many dictionaries, they can seem to be a given, rather than the (often very tentative) results of extensive research. This book is intended for anyone who has taken the important first step of realizing that etymologies are the result of research, and would like to discover something about the nature of that research, and the principles and methodologies which underlie it."
• (countable) The direct origin of a name, as in who someone was named after.
  "I'm sure you know the etymology of your name, Goodspeed."