Old Norse þyrstr

← Proto-Germanic *þurstiz (inherited)

← Proto-Germanic *þurstuz (mention)

← Proto-Indo-European *ters- (root)

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

→ Danish tørst (mention)

→ Faroese tystur (inherited)

→ Icelandic þyrstur (inherited)

→ Norwegian Bokmål tørst (derived)

→ Norwegian Nynorsk tørst (derived)

→ Norwegian Nynorsk tørste (derived)

→ Swedish törst (derived)