Welsh allwedd

← Breton alc'houez (cognate)

← Proto-Brythonic *alchwedd (inherited)

← Proto-Brythonic achlwedd (derived)

← Proto-Indo-European *(s)kleh₂w- (derived)

← Proto-Indo-European *n̥- (mention)

← Latin claudo (cognate)

→ Welsh allweddell (affix)

→ Welsh allweddi (affix)

→ Welsh allweddol (affix)

→ Welsh allweddair (affix)