1540s, probably from Old English wice "Applied generally or vaguely to various trees having pliant branches" [OED], from wican "to bend" (from PIE root *weik- (2) "to bend, to wind") + hæsel, used for any bush of the pine family (see hazel (n.)). The North American bush, from which a soothing lotion is made, was so called from 1670s. This is the source of the verb witch in dowsing.
Old English plante "young tree or shrub, herb newly planted, a shoot or strip recently sprouted from seed," from Latin planta "sprout, shoot, cutting" (source of Spanish planta, French plante), which is perhaps from an unattested verb *plantare "to drive in with the feet, push into the ground with the feet," or perhaps "to level the earth," from planta "sole of the foot," from nasalized form of PIE root *plat- "to spread." German Pflanz, Irish cland, Welsh plant also are from Latin.
Broader sense of "any small vegetable life, vegetation generally" (sometimes popularly excluding trees), "an individual living being with material organization but not animal in nature" is recorded by 1550s.
Most extended usages are from the verb, on the notion of "something planted;" such as "construction for an industrial process," 1789, at first with reference to the machinery, tools, apparatus, etc., later also the building; also slang meaning "a spy" (1812). Many of these follow similar developments in the French form of the word.
Old English hæsl, hæsel, from Proto-Germanic *hasalaz (source also of Old Norse hasl, Middle Dutch hasel, German hasel), from PIE *koselo- "hazel" (source also of Latin corulus, Old Irish coll "hazel"). Shakespeare ("Romeo and Juliet," 1592) was first to use it (in print) in the sense of "reddish-brown color of eyes" (in reference to the color of ripe hazel-nuts), when Mercutio accuses Benvolio:
Thou wilt quarrell with a man for cracking Nuts, hauing no reason, but because thou hast hasell eyes.
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]
Old English plantian "put or set in the ground to grow" (transitive and intransitive), also "introduce and establish, set up for the first time," from Latin *plantare "to plant, drive in with the feet" (see plant (n.)). Reinforced by cognate Old French planter.
Without reference to growing, "to insert firmly," late 14c. Of colonies, "introduce and establish new settlers in," from c. 1300. Figuratively, of ideas, etc., from early 15c. Meaning "to station (someone) for a surreptitious or secret purpose" is by 1690s; sense of "place (something) in a concealed place to mislead a later discoverer" is by 1865. In pugilistic slang, "to land, deliver" (a blow, etc.) by 1808. Meaning "to bury" is U.S. slang from U.S., 1855. Related: Planted; planting.
1853 in the literal sense (witch-hunting is from 1630s), from witch (n.) + hunt (n.). The extended sense is attested from 1919, American English, later re-popularized in reaction to Cold War anti-Communism.
Senator [Lee S.] Overman. What do you mean by witch hunt?
Mr. [Raymond] Robins. I mean this, Senator. You are familiar with the old witch-hunt attitude, that when people get frightened at things and see bogies, then they get out witch proclamations, and mob action and all kinds of hysteria takes place. ["Bolshevik Propaganda," U.S. Senate subcommittee hearings, 1919]