alchemy

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A medieval chemical philosophy having as its asserted aims the transmutation of base metals into gold, the discovery of the panacea, and the preparation of the elixir of longevity.
• noun A seemingly magical power or process of transmuting.

from The Century Dictionary.

• noun Medieval chemistry; the doctrines and processes of the early and medieval chemists; in particular, the supposed process, or the search for the process, by which it was hoped to transmute the baser metals into gold.
• noun Any magical or mysterious power or process of transmuting or transforming.
• noun Formerly, a mixed metal used for utensils, a modification of brass: so called because believed to have been originally formed by the art of alchemy; hence, an imitation, as alchemy was supposed to be of brass: used figuratively by Milton for a trumpet.
• noun Formerly also spelled alchymy.

from the GNU version of the Collaborative International Dictionary of English.

• noun An imaginary art which aimed to transmute the baser metals into gold, to find the panacea, or universal remedy for diseases, etc. It led the way to modern chemistry.
• noun obsolete A mixed metal composed mainly of brass, formerly used for various utensils; hence, a trumpet.
• noun Miraculous power of transmuting something common into something precious.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun uncountable The ancient search for a universal panacea, and of the philosopher's stone, that eventually developed into chemistry.
• noun countable The causing of any sort of mysterious sudden transmutation.
• noun computing, slang, countable Any elaborate transformation process or algorithm.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a pseudoscientific forerunner of chemistry in medieval times
• noun the way two individuals relate to each other