Where does “murach” come from?

murach (Old Irish) comes from Latin murex, from Ancient Greek μύαξ, from Ancient Greek μῦς, from Proto-Hellenic *mū́s, from Proto-Indo-Iranian múHs, from Proto-Indo-European múh₂s — mouse.

murach (Old Irish): shellfish; murex, purple-fish

Definitions

shellfish; murex, purple-fish

Ancestry of “murach”, step by step

Step	Language	Word	Meaning
1	Latin	murex	A shellfish used as a source of the dye Tyrian...
2	Ancient Greek	μύαξ	sea mussel
3	Ancient Greek	μῦς	mouse; A type of mussel; A type of whale
4	Proto-Hellenic	*mū́s	—
5	Proto-Indo-Iranian	múHs	mouse
6	Proto-Indo-European	múh₂s	mouse

Every word from Proto-Indo-European múh₂s →Every word from Proto-Indo-Iranian múHs →Every word from Proto-Hellenic *mū́s →