Why the K in Magick?
The Anglo-Saxon "k" in magick is a means of indicating the kind of magick being performed, thereby differentiating it from stage magic involving slight-of-hand, like Houdini. It was introduced by Aleister Crowley, a famed practitioner of magick also called "The Beast".
If one wants to put more meaning into it, here is information on the signficance of K. "K" is the eleventh letter of several alphabets, and eleven is the principal number of magick (as well as a master number in astrology) because it is the number attributed to the Qliphoth (the under-world of demonic and chaotic forces that have to be overcome before magick can be performed). "K" has other magical implications; it corresponds to the power or shakti aspect of creative energy as k is the ancient Egyptian khu, the magical power. Specifically, it stands for kteis (vagina), the compliment to the wand (or phallus) which is used by the magician in certain aspects of the Great Work.