HADITH TERMINOLOGY
موضوع
mawḍūʿ
Fabricated — words someone invented and falsely placed in the Prophet's mouth. Not a hadith at all.
This is the only grade that makes a positive claim of falsehood. Ibn al-Ṣalāḥ defines it as "the invented, the manufactured" (al-mukhtalaq al-maṣnūʿ). Al-Nawawī calls it "the worst of the weak".
It is forbidden to transmit it, for anyone who knows its condition, in any sense whatsoever, except together with a statement that it is a fabrication.
Fabrication is established by the fabricator's own confession, by something equivalent to a confession, or by indications in the narrator or in the text itself — Ibn al-Ṣalāḥ mentions among these "the feebleness of its wording and its meanings".
Whether a particular hadith really is fabricated is frequently disputed. Al-Nawawī criticises Ibn al-Jawzī's al-Mawḍūʿāt by name: "he included much for which there is no evidence of fabrication; rather it is merely weak." So a claim that "scholars say this is fabricated" always needs a WHO.