Strong’s Greek
G5587 — psithurismos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
ψιθυρισμός
psithurismos — pronounced psith-oo-ris-mos'
from a derivative of psithos (a whisper; by implication, a slander; probably akin to 5574); whispering, i.e. secret detraction:--whispering. see GREEK for 5574
1 occurrence in the KJV.
2 Corinthians 12:20
For I fear, lest, when I come, I shall not find you such as I would, and that I shall be found unto you such as ye would not: lest there be debates, envyings, wraths, strifes, backbitings, whisperings, swellings, tumults: