Etymology (Gr.), the investigation of the origin or derivation and of the original signification of words. It forms a subsidiary part of the science of comparative philology, and, though it has occupied the attention of the learned and the curious in every age, it is only within the 19th century that its study has been pursued on really scientific principles. Ignorance, or what is still more dangerous, half-knowledge, has often suggested false etymologies, and many more have sprung from that excess of confident and self-sufficient ingenuity which will not take plain words like beef-eater and welsh-rabbit for what they are. Folk-etymology, properly so called, has played an important rôle in the development of languages. The words that the people have known from their infancy are for them things, but it is quite different with the new terms they meet. These arrest their curiosity, and, as they believe that every word has its signification, they seek for this, guided by resemblances of sound with words already known, and consequently reach conclusions often hopelessly distorted by false analogies. We see the same illogical process in the Old Testament interpretation of personal names, applied conveniently after the fact; in the Homeric explanations of the names of gods and men; in the quaint etymologies so common in medieval writers, and in such moderns as Thomas Fuller; in the vagaries of our Celtic topographers; and even in the pages of some modern dictionaries it is possible to find such a statement as that the English word news is derived from a certain conjunction of the points of the compass, N. E. W. and S. These whimsical etymologies were laughed at by Dean Swift, whose ostler = out-stealer, was a stroke of genius, but have not yet disappeared; and, indeed, the modern Englishman's ideas of method in etymology are hardly at all beyond the point attained by the grammarians of Alexandria and by Varro among the Romans. It was the birth of philology and the study of the languages of the East that made a scientific etymology possible. It no longer sought the relations of the words of a single language exclusively within itself, but extended its view to the whole group of cognate tongues, or, wider still, to a whole family, and became a new science under the name of Comparative Grammar. Grimm's Law was the first finger-post that pointed out the path; among his greatest successors are Curtius and Fick. The Teutonic revival within England in the 19th century commenced the history of English upon an historical method, from which has grown a really scientific English etymology, as seen in the dictionaries of Professor Skeat and Dr Murray. No more useful chart of warning could be given than the former's canons for etymology: 'Before attempting an etymology, ascertain the earliest form and use of the word, and observe chronology. If the word be of native origin, we should next trace its history in cognate languages. If the word be borrowed, we must observe geography and the history of events, remembering that borrowings are due to actual contact.' See Curtius, Grundzüge der Griechischen Etymologie (5th ed. 1879); Fick, Vergleichendes Wörterbuch der Indo-germanischen Sprachen (3d ed. 4 vols. Gött. 1874-76); Karl Andresen, Ueber Deutsche Volksetymologie (1876); and A. S. Palmer's Folk-Etymology (1882).
Etymologicum Magnum is the name of a Greek lexicon, the oldest of the kind, professing to give the roots of the words. It appears to belong to the 10th century; the author's name is unknown. The etymologies are mere guesses, sometimes right, often wildly absurd; but the book is valuable, as containing many traditions and notices of the meanings of old and unusual words. There is an edition by Schäfer (Leip. 1816); one by Sturz, called Etymologicum Gudianum (Leip. 1818); and another by Gaisford (Oxford, 1849).