Where does “susurrar” come from?

susurrar (Spanish) comes from Latin susurrō, from Latin susurrus, from Proto-Indo-European swēr- — heavy.

susurrar (Spanish): to whisper, susurrate

Definitions

Step	Language	Word	Meaning
1	Latin	susurrō	—
2	Latin	susurrus	whisper; murmur
3	Proto-Indo-European	swēr-	heavy

susurrar — Etymology, Origin & Word History | Etymology Explorer