If you want a "male" term for witch, then please tell me how would female necromancers, warlocks, shamans, druids and all other usually commonly male associated terms be called?
Necromancess, Warlockess, Shamaness, Druidess and Princess.
If the name is such an immersion breaker (and I can understand that), mod it ?
I can't see that being hard to do, but as it stand I think Witch is 100% appropriate.
(well ok on necromancer you removed one) but makes you wonder what does that females of those classes 
I mean when you look on letters 