magician vs magus

magician and magus both are nouns.

Word	Noun	Adjective	Verb	Adverb
magician	Yes	No	No	No
magus	Yes	No	No	No

As nouns, magus is a hyponym of magician; that is, magus is a word with a more specific, narrower meaning than magician:

Other hyponyms of magician include enchanter, exorciser, exorcist, sorceress, witch doctor.

magician (noun)	magus (noun)
one who practices magic or sorcery	a magician or sorcerer of ancient times
someone who performs magic tricks to amuse an audience	a member of the Zoroastrian priesthood of the ancient Persians