Mithras

Etymology
..

Proper noun

 * 1) A Roman god, cult figure of the 2nd-to-4th-century Roman mystery religion known as the "Mysteries of Mithras" (now colloquially Mithraism)

Etymology
Probably via from some unattested  intermediary, ultimately from vocative  (cf. Mithra).

Until the 1970s, the character of Roman Mithras was widely assumed to be a continuation of that of Iranian Mithra (and thus also of Indo-Iranian ). This notion is no longer followed today, and it is generally agreed that borrowing (e.g. of the name) does not constitute continuation.

Proper noun

 * 1) A Roman god, cult figure of the 2nd–4th century Roman mystery religion known as the "Mysteries of Mithras" (now colloquially Mithraism)