leap yearyoudaoicibaDictYouDict[leap year 词源字典]
leap year: [14] The inspiration for the term leap year is probably simply that in such a year the day on which any given date falls ‘jumps’ one day ahead of where it would have been in an ordinary year. The metaphorical application of the notion of ‘jumping’ to this phenomenon predates the first record of the term leap year: medieval Latin, for instance, used the term saltus lunae ‘moon’s jump’ for the nineteen-yearly omission of a day from the lunar calendar, and this was translated into Old English as mōnan hlyp ‘moon’s leap’.
[leap year etymology, leap year origin, 英语词源]
Ramadan (n.)youdaoicibaDictYouDict
ninth month of the Muslim year, 1590s, from Arabic Ramadan (Turkish and Persian ramazan), originally "the hot month," from ramida "be burnt, scorched" (compare Mishnaic Hebrew remetz "hot ashes, embers"). In the Islamic lunar calendar, it passes through all seasons in a cycle of about 33 years, but evidently originally it was a summer month.