mice

The story

1. Proto-Germanic · derived from*mūs“mouse”
2. Proto-Germanic · inherited from*mūsiz“mice”
3. Old English · inherited frommȳs“mice”
4. Middle English · inherited frommys
5. English todaymice

From Middle English mys, mice, muis, mise, mis, from Old English mȳs (“mice”), from an umlauted form of Proto-Germanic *mūsiz (“mice”), nominative and vocative plural of Proto-Germanic *mūs (“mouse”). Compare Scots mice, mise, myse, myce (“mice”), West Frisian mûzen (“mice”), Dutch muizen (“mice”), German Mäuse (“mice”), Swedish möss (“mice”), Faroese mýs (“mice”), Icelandic mýs (“mice”). More at mouse.