Where does “merthyr” come from?

merthyr (Middle Welsh) comes from Proto-Brythonic *merθɨr, from Latin martyr, from Ancient Greek μάρτυρ, from Ancient Greek μάρτυς — witness; martyr.

Ancestry of “merthyr”, step by step

StepLanguageWordMeaning
1Proto-Brythonic*merθɨrmartyr
2Latinmartyrmartyr, especially a Christian martyr
3Ancient GreekμάρτυρAeolic form of μᾰ́ρτῠς
4Ancient Greekμάρτυςwitness; martyr

Words derived from “merthyr”

Every word from Ancient Greek μάρτυς →Every word from Ancient Greek μάρτυρ →Every word from Latin martyr →