Etymology is the only linguistic subdiscipline that is uniquely historical in its study of the relevant linguistic data and one of the oldest fields in Romance linguistics. The concept of etymology as practiced by Romanists has changed over the last 100 years. At the outset, Romance etymologists took as their brief the search for and identification of individual word origins. Starting in the early 20th century, various specialists began to view etymology as the preparation of the complete history of all facets of the evolution over time and space of the words or lexical families being studied. Identification of the underlying base was only the first step in the process. From this perspective, etymology constitutes an essential element of diachronic lexicology, which covers all formal, semantic, and syntactic facets of a word’s evolution, including, if appropriate, the circumstances leading to its demise and replacement.