A false accusation; calumny.
The word occurs twice in the Qur’an:
Surah iv. 112: “Whose commits a fault or sin, and throws it upon one who is innocent, he hath to bear calumny (buhtan) and manifests in.”
Surah xxiv. 15: – “And why did ye not say when ye heard it, ‘It is not for us to speak of this’? Celebrated be Thy praises, this is a mighty calumny (buhtan).” [BACKBITING]
Based on Hughes, Dictionary of Islam