Old Irish frith-

← Proto-Celtic *writ- (inherited)

← Welsh wrth (cognate)

← Welsh gwrth- (mention)

← Proto-Indo-European *wert- (root)

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

← Latin versus (cognate)

→ Irish frith- (inherited)

→ Old Irish frisaccai (affix)

→ Old Irish frisben (affix)

→ Old Irish frisgair (affix)

→ Old Irish frisoirc (affix)

→ Old Irish frecndairc (affix)

→ Old Irish frithaire (affix)

→ Old Irish friscuirethar (affix)