It seems that to trap the word in the confines of its etymology is to constrict the vastness and subtleties of its meanings. Wikipedia’s take on it might be of interest http://en.wikipedia.org/wiki/Alchemy
The simple derivation from the Oxford dictionary is this: late Middle English: via Old French and medieval Latin from Arabic al-kīmiyā’, from al ‘the’ +kīmiyā’ (from Greek khēmia, khēmeia ‘art of transmuting metals’). Though I doubt that the obsession with ‘transmuting metals’ was actually in the fundament of the word’s original usage. Does anyone know the exact translation of the Greed khemia?
Wikipedia starts with listing the three major goals of alchemy: the creation of the fabled philosopher’s stone; the ability to transmute base metals into the noble metals (gold or silver); and development of an elixir of life, which would confer youth and longevity. I think we could argue that, whether literally or figuratively, TSK engages all three activities.