houryoudaoicibaDictYouDict[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]
tideyoudaoicibaDictYouDict
tide: [OE] Tide originally meant ‘time’ – as in the tautologous ‘time and tide wait for no man’. Like the related German zeit, Dutch tijd, and Swedish and Danish tid, all of which mean ‘time’, it comes from a prehistoric Germanic *tīdiz. This was derived from the base *- (source also of English time), which in turn went back to the Indo-European base *- ‘divide, cut up’ – so etymologically the word denotes ‘time cut up, portion of time’.

This notion of a ‘period’ or ‘season’ is preserved in now rather archaic expression such as Christmastide, Whitsuntide, and noontide. The application to the rise and fall of the sea, which emerged in the 14th century, is due to the influence of the related Middle Low German tīde and Middle Dutch ghetīde, where it presumably arose from the notion of the ‘fixed time’ of the high and low points of the tide. Betide [13] was formed from the now archaic verb tide ‘happen’, a derivative of the noun.

=> betide, tidy, time
WhitsundayyoudaoicibaDictYouDict
"Pentecost," late Old English Hwita Sunnandæg "white Sunday" (see white (adj.)); possibly so called from the white baptismal robes worn by newly baptized Christians on this day. Related: Whitsuntide.