←
English thumb (cognate)
←
Proto-Germanic *þumô (derived)
←
Proto-Germanic *þūmô (mention)
←
Old Danish thumæ (inherited)
←
Old Norse *þumi (inherited)
←
Swedish tumme (cognate)
→
English thumb (cognate)
→
Old English þuma (cognate)
→
Icelandic tomma (derived)