Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
English armth
Old English iermþu (inherited)
English arm (suffix)
English th (suffix)
Middle English armthe (inherited)
Middle English earmthe (mention)
Proto-West Germanic *armiþu (inherited)
Proto-West Germanic *arm (mention)

English arm (link)
German Armut (cognate)