Old Irish blíadain

← Breton blizen (cognate)

← Proto-Celtic *blēdanī (inherited)

← Welsh blwyddyn (cognate)

← Proto-West Germanic *blait (cognate)

← Proto-Indo-European *bʰloyd- (derived)

← Cornish blydhen (cognate)

← Lithuanian blaĩvas (cognate)

← Albanian blehurë (cognate)

→ Breton bloaz (cognate)

→ Welsh blwyddyn (cognate)

→ Welsh blwydd (cognate)

→ Irish bliain (inherited)

→ Scottish Gaelic bliadhna (inherited)

→ Manx blein (inherited)

→ Cornish bledhen (cognate)