Adjective derived from the passive future participle of nefor nefari nefas, defective Latin verb which means no speak, not to say. As the passive future participle indicates obligation, nefandus means that must not be told, unspeakable, infamous, abominable, execrable, shameful, disgraceful, abhorrent, perverse, detestable, what cannot be discussed as immoral or disgusting, contrary to the will of the gods or the laws of nature. The Spanish and non-Spanish inquisitors considered ( ba ) n homosexual acts a heinous sin.