Terminology

Hadith
Hadith A hadith (pl. ahadith) is an oral report of what someone said or did.
Matn A matn is the text of a hadith.
Isnad An isnad (pl. asnad) is a list of people who were involved in the oral transmission of a hadith.
Khabar A khabar (pl. akhbar) is a hadith of the Prophet Muhammed.
Atar An atar (pl. athar) is a hadith of a Sahabi or Tabi'.
Mutawatir A mutawatir hadith is a hadith which has been narrated by several different narrators.
Ahad An ahad hadith is a hadith which has been narrated by a single narrator.
Sahih A sahih hadith is a hadith which is considered authentic.
Hasan A hasan hadith is a hadith which is considered good, but has some faults.
Da'if A da'if hadith is a hadith which is considered weak.
Munkar A munkar hadith is a hadith which has been denounced, as it contradicts a report of a stronger hadith.
Mawdu A mawdu hadith is a hadith which is considered to be fabricated.
Rawi
Rawi A rawi (pl. rawa) is a narrator of a hadith.
Rijaal A rijaal is a book containing biographies of narrators. The singular of rijaal, rajool means 'man' and refers to a narrator.
Sahabi A sahabi (pl. sahaba) is a companion of the Prophet Muhammed.
Tabi' A tabi' (pl. tabi'een) is a companion of a sahabi.
Tabi' Tabi'een A tabi' tabi'een is a companion of a tabi'.
Thiqa Thiqa A thiqa thiqa rawi is an extremely trustworthy narrator.
Thiqa A thiqa rawi is a trustworthy narrator.
Sadooq A sadooq rawi is a truthful narrator.
Sadooq La Ahwam A sadooq lah ahwam rawi is a relatively truthful narrator.
Maqbool A maqbool rawi is an acceptable narrator.
Mastur A mastur rawi is a narrator who had more than one person narrate from them, but their exact identity was unknown.
Da'if A da'if rawi is an unreliable narrator.
Majhool A majhool rawi is a narrator who is completely unknown.
Matruk A matruk rawi is a narrator who is very unreliable.
Kadhdaab kadhdaab rawi is a narrator accused of lying.