Welsh ffrwd

← Proto-Brythonic *frud (inherited)

← Proto-Celtic *srutom (inherited)

← Proto-Indo-European *srew- (root)

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

→ English stream (cognate)

→ Welsh Gwenfrewi (compound)

→ Welsh nant (link)

→ Welsh ffrydio (affix)

→ Irish sruth (cognate)

→ Scottish Gaelic sruth (cognate)

→ Old Irish sruth (cognate)