Old Norse lúka

← Proto-Germanic *lūkaną (inherited)

→ Danish nøgle (mention)

→ Danish lukke (derived)

→ Westrobothnian luuk (inherited)

→ Old Swedish luka (inherited)

→ Icelandic ljúka (derived)

→ Old Norse lykill (suffix)

→ Old Norse lykja (doublet)

→ Swedish lucka (derived)