Breton louarn

← Proto-Brythonic *llowern (inherited)

← Proto-Celtic *loɸernos (inherited)

← Proto-Indo-European *h₂wl(o)p- (derived)

← Proto-Indo-European *h₂ulp- (mention)

← Cornish lowarn (cognate)

← Old Breton louuern (inherited)

← Middle Breton louarn (inherited)

→ Latin vulpes (cognate)

→ Lithuanian lapė (cognate)

→ Latvian lapsa (cognate)