The soft whispering or rustling sound of wind in leaves, or more broadly, any hushed, sibilant murmuring that feels like speech without words. Psithurism suggests intimacy, the world confiding rather than merely moving.

From Greek psithyrizein “to whisper,” a word that nearly performs its meaning: consonants like dry leaves, vowels like breath. English keeps it as a specialist’s delight—sound named with sound.