UMLAUT, (TOmlout (Ger., sound-change). In comparative philology, the change undergone by a vowel or diphthong through the influence of a following vowel. It is, therefore, essentially a process of regressive vowel-assimilation. It oc curs frequently throughout the Indo-Germanic group, although it is a characteristic of the Germanic languages. As examples of umlaut, occasionally called mutation by English writers, may be cited Avesta rohu, 'good,' inoThi, 'soon,' but Sanskrit rasa, inalit; Armenian heant, 'I live,' but Sanskrit jiraini; Boeotian Greek rporeabas, 'table,' hut Attic rpcin-q'a; Attick Greek beside 4fµACTuS; Latin nihil, 'nothing.' from ne hilum, 'not a thing;' Vulgar Latin ri.rillum, 'banner,' butumen, 'pitch.' but Latin rexillum, bitumen; Old Irk!' cloth, 'famous,' but Greek KXuTbs; Old Church Slavic bidr in ti, 'watchful,' beside blaring, bgdri 1; Lithuanian budrg. In Germanic umlaut is caused either by i or u, The i-umlaut changes a preceding e to i, and a to e, as Gothic, 01(1 High German ist, 'is,' but Greek iari; Old High German gcsti, plural of Bast, 'host.' In Middle High German the i-umlaut changes o, u, a, a, 0, and no to a, ii, ae, oe, in, and fie respectively, as loeher, plural of loch, 'hole,' siine, plural of sun, 'son,' gacben, subjunctive of Own, 'gave,' hoercn, present of korte, 'heard,' briute, plural of brat, 'bride,' ggete, 'goodness, from gnat, 'good.' The chief i-umlauts in Anglo-Saxon are of cc, o, 5, a, and a to e, w, e, or usually y, e, and y re spectively, as Anglo-Saxon weecan, 'to wake,' Gothic tcakjan ; ha-lan, 'to heal,' from heal, 'health,' excn, plural of 010. `ox,' and gylden, 'golden,' from gold, 'gold,' Leman, 'to judge,' from dons, 'judgment teyllen, 'woolen,' from mune, 'wool;' eypan, *to proclaim.' from cyls, 'famous.' In Icelandic also the i-umlaut plays an important part.
The u-umlaut is less far-reaching than the palatalization caused by i. It does not occur in Gothic (owing probably, in part, to the deficien cies of the Gothic system of writing) or in Old, Middle, or New High German. It is found, how
ever, in Anglo-Saxon, and, highly developed, in Icelandic. In Anglo-Saxon a before u or o be comes ea, e becomes co, and i becomes io, al though these umlauts are by no means regular in their action. Examples are ealu, 'ale,' but geni tive alo , cola , Northumbrian al es; ircorod, 'folk,' beside leer od ; mioluc, 'milk,' but Gothic mituks. The principal Icelandic a-umlauts are of a to o, eto ei, e to 6, a to 5, i to y, i to y, ei to dy or ey, in to io, as to no or 0, ug to 6, at to y, la to y, and ue to 4. There are other minor umlauts. Anglo-Saxon has a palatal umlaut which changes the co and io arising from the 'breaking' of Germanic c and i before a guttural It plus a consonant to ie and later to i, y, and before palatals ea and en later became e, e. Ex amples are right, ryht, 'right,' beside reoht, Old High German rent; Wiht, 'Wight,' beside Trioht ; sex, 'knife,' beside earlier sear; ege, 'eye,' beside earlier page. In Icelandic there are traces of an a-umlaut, as in a'r, 'they' (feminine), but Old Swedish aR, Gothic os. In German umlaut survives as an important element in the inflec tion. It is found especially in nouns. as Brirder, plural of /fruiter, 'brother' (but Old High Ger man bruoder for both numbers), Siihne, plural of Sohn, 'son' (Old High German sari, sun), Halide, plural of Band, 'hand' (Old High Ger man !with, hart), Liimmer, plural of Lamm, 'lamb' (Old High German tembir, Iamb). It also characteriSes the comparative and superlative de grees of adjectives, as juny, 'young,' iiingcr, jiingst (Old High German jung, jungiro, Jung isto), and is seen in the imperfect subjunctive of certain verbs, as Nate from haben, 'to have' (Old High German ha/'M. In English there are only sporadic traces, as in men, mice, feet. as plurals of man, mouse. foot (Anglo-Saxon men. nucn, mys, fat, plurals of man, mfrs, (fit), and in causa tive verbs, as set from sit (Anglo-Saxon scttan from sit ton, Gothic sat jan from sitan, pret. sat).