Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Romanian ac
Proto-Indo-European *h₂eḱ- (derived)
Latin acus (inherited)

Italian ago (cognate)
Romanian acar (affix)
Romanian acușor (suffix)
Romanian acarniță (suffix)
Romanian acăriță (suffix)
Aromanian ac (cognate)