HADITH TERMINOLOGY
شاذ
shādhdh
A version from an otherwise reliable narrator that clashes with what stronger or more numerous narrators reported. The odd one out.
The core idea is CONTRADICTION between transmissions. The better-supported version is called maḥfūẓ (preserved); the outlier is called shādhdh.
Its presence is one of the five things that disqualifies a hadith from the grade of sahih.
This term was genuinely contested, and Ibn al-Ṣalāḥ lays out three incompatible definitions: for al-Shāfiʿī and a group of the scholars of the Hijaz, shādhdh is when a trustworthy narrator narrates something CONTRADICTING what the people narrated — not merely narrating what others did not; for al-Khalīlī, anything with only a single chain; for al-Ḥākim, what a trustworthy narrator is alone in without corroboration. Ibn al-Ṣalāḥ rejects the latter two, since they would condemn famous sound hadiths such as "actions are but by intentions". Ibn Ḥajar further differs from Ibn al-Ṣalāḥ and al-Nawawī in separating shādhdh from munkar: for him, contradiction by an acceptable narrator is shādhdh, while contradiction by a weak narrator is munkar.