Breton dek

← Proto-Brythonic *deg (inherited)

← Proto-Celtic *dekam (inherited)

← Proto-Indo-European *déḱm̥ (inherited)

→ Breton unnek (compound)

→ Breton daouzek (compound)

→ Breton pevarzek (compound)

→ Breton trizek (compound)

→ Breton eitek (compound)

→ Breton seitek (compound)

→ Breton c'hwezek (compound)

→ Breton pemzek (compound)

→ Breton naontek (compound)