Welsh chwythu

← Breton c'hwezhañ (cognate)

← Proto-Brythonic *hwɨθɨd (inherited)

← Proto-Celtic *swizdeti (inherited)

← Ancient Greek σίζω (cognate)

← Proto-Indo-European *sweysd- (inherited)

← Cornish hwytha (cognate)

← Russian свиста́ть (cognate)

← Old Irish do·infet (cognate)

→ Scottish Gaelic sèid (cognate)

→ Latin sibilus (cognate)