Where does “murmurar” come from?

murmurar (Old Spanish) comes from Latin murmurare, from Latin murmuro, from Latin murmur, from Proto-Indo-European mormur-.

Ancestry of “murmurar”, step by step

Step	Language	Word	Meaning
1	Latin	murmurare	present active infinitive of murmurō;...
2	Latin	murmuro	I murmur, mutter; I murmur or grumble at,...
3	Latin	murmur	murmur, murmuring; humming, roaring, growling,...
4	Proto-Indo-European	mormur-	—

murmurar — Etymology, Origin & Word History | Etymology Explorer