Etymological fallacy refers to the belief that a word's current meaning should be dictated by its roots. It often arises when language pundits, objecting to a "new" or different meaning for a word, resort to what they claim is the older meaning, that is, the "correct" meaning.
Letters to the Editor abound with irate language pundits complaining about how the language, like everything else around them, is going to the dogs. However, in this editor's experience, at least, such guardians of correctness and seemliness are more often than not wrong in their claims.
By way of example of this fallacy, David Crystal points out that there is literally no limit to how far back one goes and gives the example of the word nice which can be traced back to Old French, where it meant "silly", and from there to Latin, where it meant "ignorant".
A case in point is decimate, which some people claim comes from the Roman practice of punishing every tenth soldier. While this is indeed one of its 2, 2.5 or 3 meanings, it actually comes from the Medieval Latin word decimatus, which means ‘to tithe’. So, in the words of Ammon Shea, a consulting editor for American Dictionaries for Oxford University Press, "next time you attend a symposium (etymologically, drinking partner) with someone sinister (etymologically, left-handed), and they launch into a tirade about the misuse of this word, you’ll be able to decimate their argument in no time at all".
- Crystal, David. The English Language. Penguin. ISBN 0-14-100396-0
- Collins English Dictionary, decimate, retrieved 17th September 2012.
- Oxford Dictionaries, decimate, retrieved 17th September 2012.
- Merriam-Webster, decimate, retrieved 17th September 2012.
- "Does ‘decimate’ really mean ‘destroy one tenth’?" Oxford Dictionaries, retrieved 17th September 2012.