The word "Witch."
The earliest reference I could find in recognisable English was dated
A.D.1225 from a work called Juliana of unknown authorship:
"Ich hit am spat spec spur simunes much be wicche"
Following the Great Vowel Shift (A.D.1375), we can find a much clearer:
"Sayand he was ane enchantore, A wech and a trigetouyre"
(from Legendary Saints, by Clement).