المسند
al-Musnad
A collection of hadith arranged by the Companion who reported them, such as the Musnad of Ahmad ibn Hanbal.
What it means
Al-musnad is a hadith collection arranged under the names of the Companions who narrated the reports, so that all those from Abu Hurayra are grouped together, then those of another Companion. This differs from the arrangement by subject, as in the collections of al-Bukhari and Muslim. The word also describes a single report whose chain of narrators runs unbroken back to the Prophet. The best-known example is the Musnad of Ahmad ibn Hanbal, a very large collection. Another is the Musnad of Abu Dawud al-Tayalisi. Scholars use these books as sources for reports, but the collections include reports of differing grades, so each must be assessed separately.
Often misunderstood as
A musnad is not a book arranged by topic, and the word is not a mark of reliability.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 50, listed as AL MUSNAD. The definition is restated here.