Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Polish siedem
Proto-Indo-European *septḿ̥ (mention)
Proto-Slavic *sedmь (inherited)
Proto-Slavic *setь (mention)

Latvian septiņi (cognate)
Polish siedmioro (affix)
Polish siedmiokroć (affix)
Polish siedmiolatek (affix)