1An influential treatise on astronomy written by the Greek astronomer and geographer Ptolemy in the second century AD.
- ‘But once they had translated Ptolemy's Almagest, they developed astronomy so quickly that their mark is found at every step.’
- ‘Ptolemy's Almagest was a complete theory, but it involved applying a different mathematical formula for the motion of each planet and therefore did not really represent an overall unifying system.’
- ‘Ptolemy's Almagest was one of the works which Arabic scientists studied intently.’
- ‘Finally, the translation of Ptolemy's Almagest furnished important astronomical material.’
- ‘Menelaus's work formed the basis for Ptolemy's numerical solutions of spherical astronomy problems in the Almagest.’
- 1.1(in the Middle Ages) any celebrated textbook on astrology and alchemy.
Late Middle English: from Old French almageste, based on Arabic, from al the + Greek megistē greatest (composition).