Webster's Revised Unabridged Dictionary · 1913

Almagest

Almagest ({not transcribed}) , noun

[French almageste, Late Latin almageste, Arabic al-majistī, from Greek {not transcribed} (sc. {not transcribed}), the greatest composition.]

The celebrated work of Ptolemy of Alexandria, which contains nearly all that is known of the astronomical observations and theories of the ancients. The name was extended to other similar works.