houryoudaoicibaDictgodict[hour 词源字典]
hour: [13] Greek hórā (a distant relative of English year) was originally a rather vague term, denoting ‘period of time, season’. In due course it came to be applied more specifically to ‘one twelfth of a day (from sunrise to sunset)’, but as this varied in length according to the time of the year, hórā was still far from being a precise unit of time. Not until the Middle Ages (when hórā had passed via Latin hora and Old French hore into English as hour) did the term become fixed to a period of sixty minutes. (The same sort of vague relationship between ‘time’ in general or ‘period of time’ and ‘fixed period’ is shown in Swedish timme, which is related to English time but means ‘hour’; in German stunde, which originally meant ‘period of time’, but now means ‘hour’; and indeed in English tide, which in Old English times meant ‘hour’ but now, insofar as it survives as a temporal term, denotes ‘season’ – as in Whitsuntide.) English horoscope [16] comes ultimately from Greek hōroskópos, a compound which meant literally ‘observer of time’ – that is, of the ‘time of birth’.
=> horoscope, year[hour etymology, hour origin, 英语词源]
hour (n.)youdaoicibaDictgodict
mid-13c., from Old French hore "one-twelfth of a day" (sunrise to sunset), from Latin hora "hour, time, season," from Greek hora "any limited time," from PIE *yor-a-, from root *yer- "year, season" (see year). Greek hora was "a season; 'the season;'" in classical times, sometimes, "a part of the day," such as morning, evening, noon, night.

The Greek astronomers apparently borrowed the notion of dividing the day into twelve parts (mentioned in Herodotus) from the Babylonians (night continued to be divided into four watches), but as the amount of daylight changed throughout the year, the hours were not fixed or of equal length. Equinoctal hours did not become established in Europe until the 4c., and as late as 16c. distinction sometimes was made between temporary (unequal) hours and sidereal (equal) ones. The h- has persisted in this word despite not being pronounced since Roman times. Replaced Old English tid, literally "time" (see tide (n.)) and stund "period of time, point of time, hour" (compare German Stunde "hour"), As a measure of distance ("the distance that can be covered in an hour") it is recorded from 1785.