Backbiting- mere words-but they are words that bring upon the one who utters them shame and ignominy and that consign him to the Fire. Such a person has giben in to his vain desires and succumbed to his destructive tendencies.
The Prophet (Peace be upon him) said: ' A man might speak a word without thinking about its implications, but becuase of i, he will plunge in the hellgire further than the distance between the east and west' [sahih bukhari (6477) and shih muslim (2988)]
A muslim utters a word whereby he/she describes his Muslim brother or sister in a negative way - etiher explicitly or impliclicitly - and it plunges the speaker into clear and evident loss. And what could be a greater loss that for a person to say something that does nothing for him but rob him of his blessings and of the rewards for his good deeds?