1. To study, to trace, or to describe the origins and developments of words, or to make a suggestion as to a word's possible origin and development.
2. To construct the history of words: The lexicographer spent a great deal of time searching into the origins of words and etymologizing their meanings from their simple roots.
3. To give the derivation or to suggest an origin and historical development of language forms for a word or words: Although he is not trained in linguistics, Mathew's hobby is etymologizing various vocabulary terms.