Folk etymology or reanalysis – sometimes called pseudo-etymology, popular etymology, or analogical reformation – is a change in a word or phrase resulting from the replacement of an unfamiliar form by a more familiar one. The form or the meaning of an archaic, foreign, or otherwise unfamiliar word is reanalyzed as resembling more familiar words or morphemes. Rebracketing is a form of folk etymology in which a word is broken down or "bracketed" into a new set of supposed elements. Back-formation, creating a new word by removing or changing parts of an existing word, is often based on folk etymology.
The term folk etymology is a loan translation from German Volksetymologie, coined by Ernst Förstemann in 1852.
Folk etymology is a productive process in historical linguistics and language change. Reanalysis of a word's history or original form can affect its spelling, pronunciation, or meaning. This is frequently seen in relation to loanwords or words that have become archaic or obsolete.
Examples of words created or changed through folk etymology include the English dialectal form , originally from Greek ἀσπάραγος ("asparagus") remade by analogy to the more familiar words sparrow and grass, or the word burger, originally from Hamburg + -er ("thing connected with"), but understood as ham + burger.
The technical term "folk etymology" refers to a change in the form of a word caused by erroneous popular beliefs about its derivation. The English word is a translation of the German term Volksetymologie, coined by Ernst Förstemann. Förstemann noted that in addition to scientific etymology based on careful study in philology, there exist scholarly but often unsystematic accounts, as well as popular accounts for the history of linguistic forms. Until academic linguists developed comparative philology and described the laws underlying sound changes, the derivation of words was a matter mostly of guess-work. Speculation about the original form of words in turn feeds back into the development of the word and thus becomes a part of a new etymology.