The answer to your question would be that the etimology of a word is its history and development. Etimology is the study of the history of words, their origins, and how their form and meaning have changed over the years.
For instance, the etimology of the verb "to give" states that it comes from Old English giefan (West Saxon) "to give, bestow, deliver to another; allot, grant; commit, devote, entrust" and so on.