Forms:*  α. 18 *psithurisma.

β. 18 psithurism.

*Etymology:*  < Hellenistic Greek ψιθύρισμα (also ψιθυρισμός) (noun) whispering < ancient Greek ψιθυρίζειν to whisper (probably < ψίθυρος (adjective) whispering, slanderous, of uncertain origin + -ίζειν -ize suffix, although the adjective may be derived from the verb) + -ισμα (also -ισμός ) -ism suffix.

N.E.D. (1909) gives the headword form as psithurism with the pronunciation as (psi·þiŭriz’m) ˈpsɪθjʊərɪz(ə)m .

Obs.

  Whispering; a whispering noise.

1848   L. Hunt Jar of Honey 61   There is the continuous whisper in psithurisma.

1856   J. E. Cooke Last of Foresters xxxii. 192   A murmurous laughter of mocking winds arose at times, and rustled on, and died away into the psithurisma of Theocritus.

1872   M. Collins Princess Clarice II. xix. 218   Psithurism of multitudinous leaves made ghostly music.

1883   Cent. Mag. Oct. 932/2   The popularity of our new hexameter with simple readers who know little of the Homeric roll, the Sicilian psithurisma, or Virgil’s liquid flow, has been demonstrated.