False etymology

A false etymology (pseudoetymology, paraetymology, or paretymology), sometimes called folk etymology although this is also a technical term in linguistics, is a popularly held but false belief about the origins of specific words, often originating in common-sense assumptions.

Such etymologies often have the feel of urban legends, and can be much more colorful than the typical etymologies found in dictionaries, often involving stories of unusual practices in particular subcultures (e.g. Oxford students from non-noble families being supposedly forced to write sine nobilitate by their name, soon abbreviated to s.nob., hence the word snob). Many recent examples are "backronyms" (acronyms made up to explain a term), as in snob, and posh for "port outward, starboard homeward"; many other sourced examples are listed in the article on backronyms.

Source and influence of false etymologies

Erroneous etymologies can exist for many reasons. Some are reasonable interpretations of the evidence that happen to be false. For a given word there may often have been many serious attempts by scholars to propose etymologies based on the best information available at the time, and these can be later modified or rejected as linguistic scholarship advances. The results of medieval etymology, for example, were plausible given the insights available at the time, but have often been rejected by modern linguists. The etymologies of humanist scholars in the early modern period began to produce more reliable results, but many of their hypotheses have also been superseded.