cologne (n.) Look up cologne at Dictionary.com
1814, Cologne water, loan-translation of French eau de Cologne, literally "water from Cologne," from the city in Germany (German Köln, from Latin Colonia Agrippina) where it was made, first by Italian chemist Johann Maria Farina, who had settled there in 1709. The city seems to have been known in English generally by its French name in 18c.
eau (n.) Look up eau at Dictionary.com
French for "water," from Old French eue (12c.), from Latin aqua "water, rainwater" (see aqua-). Brought into English in combinations such as eau de vie "brandy" (1748), literally "water of life;" eau de toilette (1907). For eau de Cologne see cologne.
cullen Look up cullen at Dictionary.com
in some uses it represents an Englishing of Cologne, the city in Germany. As a surname it can be this or from Cullen, Banffshire.
saturation (n.) Look up saturation at Dictionary.com
1550s, formed in English from saturate, or else from Late Latin saturationem (nominative saturatio), noun of action from past participle stem of saturare. Saturation bombing is from 1942, first in reference to Allied air raid on Cologne, Germany.
air raid (n.) Look up air raid at Dictionary.com
1914, from air (n.1) + raid (n.); originally in reference to British attacks Sept. 22, 1914, on Zeppelin bases at Cologne and Düsseldorf in World War I. The German word is Fliegerangriff "aviator-attack," and if Old English had survived into the 20th century our word instead might be fleogendeongrype.
One didn't dare to inhale for fear of breathing it in. It was the sound of eighteen hundred airplanes approaching Hamburg from the south at an unimaginable height. We had already experienced two hundred or even more air raids, among them some very heavy ones, but this was something completely new. And yet there was an immediate recognition: this was what everyone had been waiting for, what had hung for months like a shadow over everything we did, making us weary. It was the end. [Hans Erich Nossack, "Der Untergang," 1942]
witch (n.) Look up witch at Dictionary.com
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 *weg- (2) "to be strong, be lively" (see wake (v.)).

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." 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" 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]