The name "Mordecai" is of uncertain origin but is considered identical to the name Marduka or Marduku

The name "Mordecai" is of uncertain origin but is considered identical to the name Marduka or Marduku (Elamite: 𒈥𒁺𒋡), attested as the name of up to four Persian court officials in thirty texts (the Persepolis Administrative Archives) from the period of Xerxes I and his father Darius.[10] The Talmud (Menachot 64b and 65a) relates that his full name was "Mordechai Bilshan" (which occurs in Ezra 2:2 and Nehemiah 7:7, albeit likely as two separate names in sequence). Hoschander interpreted this as the Babylonian "Marduk Belshunu" (𒀭𒀫𒌓𒂗𒋗𒉡, dAMAR.UTU-EN-šu-nu, meaning "Marduk is their lord") "Mordecai" being thus a hypocorism. https://en.wikipedia.org/wiki/Mordecai Marx is a Germanised form of the Jewish family name Mordechai. It is also possibly derived from Marcus. https://en.wikipedia.org/wiki/Marx_(surname)#:~:text=Marx%20is%20a%20Germanised%20form,also%20possibly%20derived%20from%20Marcus.