"Witch" comes from the Old English word wicce "female magician, sorceress", the feminine of wicca, "sorcerer, magician", and derived from wiccian meaning "to practice magic", but there's linguistic evidence that this general word may have meant specific skills earlier, possibly including "necromancy", "soothsaying", "skill with drugs/herbs" or even "skill with horses" (but perhaps not all of these things) - e.g. see here [http://www.etymonline.com/index.php?term=witch&allowed_in_frame=0].
Nowadays I think that the word has been appropriated by different groups for different uses. The Hollywood meaning (probably the most popular) means "sorceress", possibly (but not always) with necromantic overtones. Some sects of Christianity (arguably the next most popular usage in English) treat it as meaning "necromantic or diabolic magician". Various neopagan and satanic groups have also appropriated the word to mean anything from "soothsayer" to "necromancer" and "diabolist".
I personally don't use the word, except in fiction. People like to believe in magic, but magic has never passed routine clinical testing, and psychology explains magical belief better than self-proclaimed witches do.
Age: 41-50.