Where does “rounen” come from?

rounen (Middle English) comes from Old English rūnian, from Frankish rūnōn, from Proto-Germanic rūnōną, from Proto-Indo-European (e)rewə-.

Ancestry of “rounen”, step by step

Step	Language	Word	Meaning
1	Old English	rūnian	to whisper, talk low, talk secrets, consipre,...
2	Frankish	rūnōn	to whisper; to whisper, round
3	Proto-Germanic	rūnōną	to talk secrets, whisper, decide
4	Proto-Indo-European	(e)rewə-	—