Magic potion (6)
I believe the answer is:
elixir
'magic potion' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elixir that I've seen before include "Magical or medicinal potion" , "Something believed to cure all ills" , "Philosopher's stone" , "wonder drug" , "The drink that gives eternal life" .)