Where does “Tróndur” come from?

Tróndur (Faroese) comes from Old Norse Þróndr, from Old Norse þróask, from Proto-Germanic *þrōwōną.

Ancestry of “Tróndur”, step by step

Step	Language	Word	Meaning
1	Old Norse	Þróndr	—
2	Old Norse	þróask	—
3	Proto-Germanic	*þrōwōną	—