Family name origins & meanings
- German : habitational name from a place called Themar (between Meiningen and Coburg).
- Possibly an altered spelling of the French family name Demars, a habitational name for someone from any of the places called Mars, for example in the Ardennes, Creuse, Gard, Loire, and Loire-Inférieure. The place name is from the personal name Martius, the name of the proprietor of the villa.