Not attested before the Qurʾān. Theorised to come from Ancient Greek διάβολος (diábolos, “devil, accuser, slanderer”). Alternatively, it has been maintained to originate from the trilateral root ب ل س (b l s) with the meaning of "despairing [of God's mercy] or confounded [and unable to see the right course]" from the verb أَبْلَسَ (ʔablasa). This would, however, require the trilateral root to take the form if'īl which, excepting إحليل, is usually associated with words of non-Arabic origin (see: إدريس, إكليل, إنجيل, إبريز, and إبريق).