Where does “mussel-crusher” come from?

mussel-crusher (English) comes from English mussel, from Middle English muscle, from Old English muscle, from Proto-Germanic *muskulā, from Latin muscula, from Latin mūsculus, from Ancient Greek μῦς, from Proto-Hellenic *mū́s — mouse.

Ancestry of “mussel-crusher”, step by step

mussel-crusher traces back through two separate lines of ancestry.

via English mussel

StepLanguageWordMeaning
1EnglishmusselAny of several groups of bivalve shellfish with...
2Middle Englishmusclemussel bivalve
3Old Englishmusclemussel
4Proto-Germanic*muskulā
5LatinmusculaDiminutive of musca
6Latinmūsculusa small mouse
7Ancient Greekμῦςmouse; A type of mussel; A type of whale
8Proto-Hellenic*mū́s
9Proto-Indo-IranianmúHsmouse
10Proto-Indo-Europeanmúh₂smouse

via English crusher

StepLanguageWordMeaning
1EnglishcrusherSomeone or something that crushes; A machine...
2EnglishcrushA violent collision or compression; a crash;...
3Middle Englishcruschento crush, smash, squeeze, squash
4Old Frenchcroissirto crush; to break; to crack; to snap; to crack;...
5Late Latincruscioto brush
6Frankishkrostjanto crush, squeeze, squash
Every word from Proto-Indo-European múh₂s
mussel-crusher — Etymology, Origin & Word History | Etymology Explorer