almanacyoudaoicibaDictYouDict[almanac 词源字典]
almanac: [14] One of the first recorded uses of almanac in English is by Chaucer in his Treatise on the astrolabe 1391: ‘A table of the verray Moeuyng of the Mone from howre to howre, every day and in every signe, after thin Almenak’. At that time an almanac was specifically a table of the movements and positions of the sun, moon, and planets, from which astronomical calculations could be made; other refinements and additions, such as a calendar, came to be included over succeeding centuries.

The earliest authenticated reference to an almanac comes in the (Latin) works of the English scientist Roger Bacon, in the mid 13th century. But the ultimate source of the word is obscure. Its first syllable, al-, and its general relevance to medieval science and technology, strongly suggest an Arabic origin, but no convincing candidate has been found.
[almanac etymology, almanac origin, 英语词源]
almanac (n.)youdaoicibaDictYouDict
late 14c., attested in Anglo-Latin from mid-13c., via Old French almanach or Medieval Latin almanachus, which is of uncertain origin. It is sometimes said to be from a Spanish-Arabic al-manakh "calendar, almanac," but possibly ultimately from Late Greek almenichiakon "calendar," which is said to be of Coptic origin.

This word has been the subject of much speculation. Originally a book of permanent tables of astronomical data; one-year versions, combined with ecclesiastical calendars, date from 16c.; "astrological and weather predictions appear in 16-17th c.; the 'useful statistics' are a modern feature" [OED].