Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Welsh -aeth
← Breton -ezh (cognate)
← Proto-Brythonic *-aɨθ (inherited)
← Proto-Celtic *axtā (inherited)
← Irish -acht (cognate)
← Scottish Gaelic -achd (cognate)
← Manx -aght (cognate)
← Cornish -eth (cognate)

→ Welsh trafodaeth (affix)
→ Welsh llywodraeth (affix)
→ Welsh poblogaeth (affix)
→ Welsh pennaeth (affix)
→ Welsh gwybodaeth (affix)
→ Welsh genedigaeth (affix)
→ Welsh swyddogaeth (affix)
→ Welsh ymerodraeth (affix)
→ Welsh amheuaeth (affix)
→ Welsh marwolaeth (affix)
→ Welsh cefnogaeth (suffix)
→ Welsh gweinidogaeth (affix)
→ Welsh Natsïaeth (affix)
→ Welsh gwrogaeth (affix)
→ Welsh defodaeth (affix)
→ Welsh etholaeth (affix)
→ Welsh anghymeradwyaeth (affix)
→ Welsh abadaeth (affix)
→ Welsh terfysgaeth (affix)
→ Welsh cystadleuaeth (affix)
→ Welsh cecraeth (affix)
→ Welsh rhwystredigaeth (affix)
→ Welsh deiliadaeth (affix)
→ Welsh daliadaeth (affix)
→ Welsh -aethau (compound)
→ Welsh cyflogaeth (affix)
→ Welsh argraffiadaeth (affix)
→ Welsh beirniadaeth (affix)
→ Welsh gwasanaeth (suffix)
→ Welsh Cristnogaeth (affix)
→ Welsh mynachaeth (affix)
→ Welsh lleianaeth (affix)
→ Welsh adeiladaeth (affix)
→ Welsh llawfeddygaeth (affix)
→ Welsh trefedigaeth (affix)
→ Welsh aelodaeth (suffix)
→ Welsh tywysogaeth (affix)
→ Welsh perchentyaeth (affix)
→ Welsh rhwymedigaeth (affix)
→ Cornish -ieth (cognate)