魔術師 also means magician or sorcerer, often with a slightly more occult or scholarly nuance, but largely interchangeable with 魔道士 in fantasy settings.
Etymology
Compound of 魔 (ma, 'demon/magic'), 道 (dō, 'way/path'), and 士/師 (shi, 'person/specialist'). The spelling variants reflect different nuances of the practitioner's role, but all refer to a magic user in modern fantasy contexts.