In Psalms 15:3, the rendering of a word which means to run about tattling, calumniating; in Proverbs 25:23, secret talebearing or slandering; in Romans 1:30 and 2 Corinthians 12:20, evil-speaking, maliciously defaming the absent.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Backbite'". "Easton's Bible Dictionary".