1. 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.
2. A seemingly magical power or process of transmuting: "He wondered by what alchemy it was changed, so that what sickened him one hour, maddened him with hunger the next" (Marjorie K. Rawlings).

[Middle English alkamie, from Old French alquemie, from Medieval Latin alchymia, from Arabic al-kīmiyā' : al-, the + kīmiyā', chemistry (from Late Greek khēmeia, khumeia , perhaps from Greek Khēmia, Egypt).]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.