Wordnet 3.0
NOUN (1)
1. 
 one who was versed in the practice of alchemy and who sought an elixir of life and a panacea and an alkahest and the philosopher's stone; 
The Collaborative International Dictionary of English v.0.48:
Alchemist \Al"che*mist\, n. [Cf. OF. alquemiste, F. alchimiste.]
   One who practices alchemy.
   [1913 Webster]
         You are alchemist; make gold.            --Shak.
   [1913 Webster] Alchemistic
WordNet (r) 3.0 (2006):
alchemist
    n 1: one who was versed in the practice of alchemy and who
         sought an elixir of life and a panacea and an alkahest and
         the philosopher's stone