almagest

noun

al·​ma·​gest ˈal-mə-ˌjest 

: any of several early medieval treatises on a branch of knowledge

Word History

Etymology

Middle English almageste, from Anglo-French & Medieval Latin, from Arabic al-majusti, the Arabic version of Ptolemy's astronomy treatise, from al the + Greek megistē (syntaxis), literally, greatest (composition)

First Known Use

14th century, in the meaning defined above