Welsh llosg

← Proto-Celtic *lowsk- (inherited)

← Proto-Indo-European (inherited)

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

← Old Cornish losc (cognate)

← Old Welsh losc (inherited)

← Old Irish losc (cognate)

← Middle Welsh llosg (inherited)

→ Welsh golosg (compound)

→ Welsh llosgfaen (compound)