branch of linguistics that deals with the origin and development of words and with the comparison of similar words, or cognates, in different languages of the same language group. In its relation to other subdivisions of linguistics, etymology stands closest to phonology; in fact, before the development of phonetic laws, no scientific or systematic means of tracing the derivation of words existed.

Origins of Philosophy.

As its own origin from the Greek (etymos, “true”; logos, “word”) shows, etymology was first used as a philosophical term. The Greek Stoics believed that words and their meanings exist in nature, as the real counterparts of things and abstract ideas, rather than as conventions invented and agreed upon by human beings. Long before the foundation of the Stoic school, however, Plato had used a method similar to modern etymology in his Cratylus, a dialogue on the meaning of words. The first formal treatise on etymology, however, was Indian, dating as far back perhaps as the 5th century bc, and was composed to explain the difficult words in the Rig-Veda, the oldest and most important of the Hindu sacred books.

Early attempts at etymology were naive and incorrect according to phonetic evolution. This primitive kind of etymology is still common and is known as popular, or folk, etymology. Among those unfamiliar with the history of words, the attempt is frequently made to etymologize them in terms of other words to which they may have some phonetic resemblance. In English, for example, the word island, properly “isle-land” (A.S. [imacr ]gland), has been explained as “land like an eye in the waters”; and asparagus (Gr. asparagos, “a sprout”) has become corrupted to “sparrowgrass” in colloquial speech.

Scientific Comparisons.

At about the beginning of the 1800s, European scholars studying Sanskrit noted its resemblance in vocabulary to Latin and Greek. The comparison of vocabularies was extended to other languages, and the idea of a common origin, an Indo-European parent language, was soon established. This, in turn, led to the establishment of certain principles concerning the sound changes that affected the forms of words in the different languages, that is, to the formulation of the phonetic laws. In the case of loan words—words borrowed from other languages—phonetic law is apparently violated, and it frequently happens that a language has two or more words derived from a single word, one being a regular phonetic development, the other a borrowed form. In this case the latter form, known by the French term mot savant, is usually differentiated in meaning from the former. Thus, in French and English such words as royal and regal are both from the Latin regalis, “kingly”; the form regal is borrowed directly from the Latin, and royal (Fr. roi, “king,” from the Latin accusative regem) is the phonetically correct form. Loan words may also undergo the regular sound changes of the language into which they have been adopted. For example, the Latin pondus, “pound,” appears in Gothic and Anglo-Saxon as pund, with unchanged consonants, but in Old High German it is subject to the action of GRIMM'S LAW, (q.v.) and becomes phunt. Thus, in etymology attention must be given to the history of words and sometimes to the records of the tribes speaking them. The English wise (as in otherwise, in no wise) is akin to the Old High German w[imacr ]s(a), modern German die Weise; but wise is a doublet of guise, the form assumed by w[imacr ]s(a) in the Romance languages, which borrowed the word from the Germanic form. The same word thus may assume different forms in the same language, and, conversely, different words may become identical in form in a specific language. The large group of homonyms in every language is sufficient proof of this process. An example of such a phenomenon in English is sound, which is a conglomerate of several originally distinct words: Anglo-Saxon gesund, “hearty”; Anglo-Saxon sund, “a body of water”; and Latin sonus, “noise.”

Etymology finds its principal application in the tracing back of words through an entire group of allied languages to a hypothetical original form. The older etymologies made inaccurate but plausible guesses along these lines; many etymologies that are perfectly sound, however, seem at first sight implausible to those who are not acquainted with phonetic laws and the principles of word formation. Etymology may be confined to a specific group of languages or dialects. Thus, it is possible to refer to Romance etymology (in which words in the Romance languages are traced back for the most part to folk-Latin originals), and to Germanic, Celtic, and Indo-Iranian etymologies, among others. All these are combined in Indo-European, or Indo-Germanic, etymology, which is the most thoroughly systematized and serves as a model for the rest.

Accidental resemblances in sound are often mistaken for phonetic mutations or proof of etymological kinship. The fact that the Latin taurus sounds like Arabic thaur, both meaning “bull,” or that the English sheriff resembles in sound the Arabic sharif, “exalted,” also used for an official of a city, implies no relationship.

Certain methods in tracing the etymology of a word have been formulated as follows. (1) The earliest form and usage of the word must be determined and its chronology respected. (2) History and geography should be followed; many words come into language through propinquity or contact. (3) Phonetic laws must be respected, particularly in their application to consonants in the Indo-European languages. (4) When two words in the same language are being studied for their related characteristics, the word that has the fewer syllables must be taken at face value to be the earlier. (5) When two words in the same language are being studied for their related characteristics and they both possess the same number of syllables, the earlier form can usually be determined by the chief vowel sound. (6) Germanic strong verbs, like Latin irregular verbs, may be assumed to be primary and all related forms to be derivative. (7) Resemblances in form, and even meaning, in unrelated languages should be ignored. (8) The explanation of an English word must also apply to its cognates. The complete etymology of a word should account for its phonetic evolution, for its source, and, if it is of foreign origin or if it is a conglomerate, for the origin of its various parts. See also LINGUISTICS,.

Etymological information can, in general, be found in the standard dictionary (or dictionaries) of a language, and in certain specialized etymological dictionaries. For the English language, the greatest source of such information is the New English Dictionary on Historical Principles (repr. as the Oxford English Dictionary, 13 vol., 1933).

For further information on this topic, see the Bibliography, sections 351. Linguistics, 360. Etymology.