1. The origin and historical development of a linguistic form as shown by determining its basic elements, the earliest known uses, and changes in form and meanings: Etymology is the science or the study of original vocabulary meanings.
2. Tracing the transmissions of words from one language to another and identifying their relationships in other languages, and reconstructing their ancestral forms when possible: The English language has borrowed many roots from Greek and Latin; so, one important aspect of historical linguistics involves the etymology of words that come from those classical languages as well as some other contributing sources; such as, French, German, Anglo-Saxon, Scandinavian, Indo-European, etc.

Through old texts and comparisons with other languages, etymology is an effort to reconstruct the history of words; when they entered a language, from what sources, and how their forms and meanings have changed.

Word origins and affixes: etymological quotes.

1. The incorrect origin for a word; an idea about the origin of a word that is generally believed but is incorrect.
2. A modification of a linguistic form according either to a falsely assumed etymology, or to a historically irrelevant analogy.
2. A popular but false notion of the origin of a word.

A few humorous examples of folk etymology

A false or incorrect description of the origin and development of a word or words: A student in Mr. Mark's class discovered a source of pseudoetymology that contained a number of false suggestions as to the possible origins and developments of vocabulary terms.