information:highlighting, structural:expansion
Etymology

The original source for their name and homeland is a directly transmitted Old Iranian geographical name which is attested as the Old Persian "Māda-" (singular masculine). The meaning of this word is not precisely known. However, the linguist W. Skalmowski proposes a relation with the proto-Indo European word "med(h)-", meaning "central, suited in the middle", by referring to the Old Indic "madhya-" and Old Iranian "maidiia-" which both carry the same meaning. The Latin medium, Greek méso, Armenian mej, and English mid are similarly derived from it.

Greek scholars during antiquity would base ethnological conclusions on Greek legends and the similarity of names. According to the Histories of Herodotus (440 BC):

The Medes were formerly called by everyone Arians, but when the Colchian woman Medea came from Athens to the Arians, they changed their name, like the Persians. This is the Medes' own account of themselves.