Marsic, Marsico or Marsian is a diamoric orientation for non-binary individuals who are attracted exclusively to men, individuals aligned with men, related to man and Solarians. It is used in replacement of androsexual. Non-binary person. It is also the name of a star in the constellation Hercules. Marsic is also a Slovenian surname. Surname of a Locen painter whose full name is Cveto Marsic.
It is not Spanish but English (although it may have a German origin). It would be another creative classification for sexual inclinations, this time for a gay, homosexual male attracted to other males. Etymologically it is related to Mars, which in English is Mars, and I do not know how it will end up being incorporated into Spanish, since "martico" sounds like Marcelo's diminutive, and looks a lot like marico. See Uranism.