late 14c., of language, "German, non-Scandinavian continental Germanic," also as a noun, "a German language;" also in Duche-lond "Germany." By mid-15c. distinguished into Higher and Lower, and used after c. 1600 in the narrower sense "Hollanders, residents of the Netherlands." From Middle Dutch duutsch, from Old High German duitisc, from Proto-Germanic *theudō "popular, national" (source of Modern German Deutsch), from PIE *teuta- "tribe" (compare Teutonic).

It corresponds to the Old English adjective þeodisc "belonging to the people," which was used especially of the common language of Germanic people (as opposed to Latin), a derivative of the Old English noun þeod "people, race, nation." The language name is first attested in Latin as theodice (786 C.E.) in correspondence between Charlemagne's court and the Pope, in reference to a synodical conference in Mercia; thus it refers to Old English. Its first use in reference to a German language (as opposed to a Germanic one) is two years later. The sense was extended from the language to the people who spoke it (in German, Diutisklant, ancestor of Deutschland, was in use by 13c.).

The sense in of the adjective in English narrowed to "of the Netherlands" in 17c., after they became a united, independent state and the focus of English attention and rivalry. In Holland, Duits (formerly duitsch) is used of the people of Germany. The old use of Dutch for "German" continued in America (Irving and Cooper still distinguish High Dutch "German" and Low Dutch "Dutch") and survives in Pennsylvania Dutch for the descendants of religious sects that immigrated from the Rhineland and Switzerland and their language.

Since c. 1600, Dutch (adj.) has been a "pejorative label pinned by English speakers on almost anything they regard as inferior, irregular, or contrary to 'normal' (i.e., their own) practice" [Rawson]. E.g. ironical Dutch treat, of each person paying for himself (1887), Dutch courage "boldness inspired by intoxicating spirits" (1809), nautical Dutch talent "any piece of work not done in shipshape style (1867), etc. — probably exceeded in such usage only by Indian and Irish — reflecting first British commercial and military rivalry and later heavy German immigration to U.S.

Dutch concert, a concert in which each one sings his own song at the same time that his neighbor sings his; or a concert in which each one sings a verse of any song he pleases, some well-known chorus being sung after each verse. [Century Dictionary, 1897]

The Dutch themselves spoke English well enough to understand the unsavory connotations of the label and in 1934 Dutch officials were ordered by their government to stop using the term Dutch. Instead, they were to rewrite their sentences so as to employ the official The Netherlands. [Rawson]

Dutch oven is from 1769; OED lists it among the words describing things from Holland, but perhaps it is here used in the slighting sense. Dutch elm disease (1927) so called because it was first discovered in Holland (caused by fungus Ceratocystis ulmi). A Dutch uncle (1838) is one who is kindly severe and direct. 

Old English wicce "female magician, sorceress," in later use especially "a woman supposed to have dealings with the devil or evil spirits and to be able by their cooperation to perform supernatural acts," fem. of Old English wicca "sorcerer, wizard, man who practices witchcraft or magic," from verb wiccian "to practice witchcraft" (compare Low German wikken, wicken "to use witchcraft," wikker, wicker "soothsayer").

OED says of uncertain origin; Liberman says "None of the proposed etymologies of witch is free from phonetic or semantic difficulties." Klein suggests connection with Old English wigle "divination," and wig, wih "idol." Watkins says the nouns represent a Proto-Germanic *wikkjaz "necromancer" (one who wakes the dead), from PIE *weg-yo-, from PIE root *weg- "to be strong, be lively."

That wicce once had a more specific sense than the later general one of "female magician, sorceress" perhaps is suggested by the presence of other words in Old English describing more specific kinds of magical craft. In the Laws of Ælfred (c. 890), witchcraft was specifically singled out as a woman's craft, whose practitioners were not to be suffered to live among the West Saxons:

Ða fæmnan þe gewuniað onfon gealdorcræftigan & scinlæcan & wiccan, ne læt þu ða libban.

The other two words combined with it here are gealdricge, a woman who practices "incantations," and scinlæce "female wizard, woman magician," from a root meaning "phantom, evil spirit."

Another word that appears in the Anglo-Saxon laws is lyblæca "wizard, sorcerer," but with suggestions of skill in the use of drugs, because the root of the word is lybb "drug, poison, charm" (see leaf (n.)). Lybbestre was a fem. word meaning "sorceress," and lybcorn was the name of a certain medicinal seed (perhaps wild saffron). Weekley notes possible connection to Gothic weihs "holy" and German weihan "consecrate," and writes, "the priests of a suppressed religion naturally become magicians to its successors or opponents." Whatever the English word's origin, the use of a "poisoner" word for "witch, sorceress" parallels that of the Hebrew word used for "witch, sorceress" in the Levitical condemnation.

In Anglo-Saxon glossaries, wicca renders Latin augur (c. 1100), and wicce stands for "pythoness, divinatricem." In the "Three Kings of Cologne" (c. 1400) wicca translates Magi:

Þe paynyms ... cleped þe iij kyngis Magos, þat is to seye wicchis.

The glossary translates Latin necromantia ("demonum invocatio") with galdre, wiccecræft. The Anglo-Saxon poem called "Men's Crafts" (also "The Gifts of Men") has wiccræft, which appears to be the same word, and by its context means "skill with horses." In a c. 1250 translation of "Exodus," witches is used of the Egyptian midwives who save the newborn sons of the Hebrews: "Ðe wicches hidden hem for-ðan, Biforen pharaun nolden he ben."

Witch in reference to a man survived in dialect into 20c., but the fem. form was so dominant by 1601 that men-witches or he-witch began to be used. Extended sense of "old, ugly, and crabbed or malignant woman" is from early 15c; that of "young woman or girl of bewitching aspect or manners" is first recorded 1740. Witch doctor is from 1718; applied to African magicians from 1836.

At this day it is indifferent to say in the English tongue, 'she is a witch,' or 'she is a wise woman.' [Reginald Scot, "The Discoverie of Witchcraft," 1584]