astrologer (n.)youdaoicibaDictYouDict[astrologer 词源字典]
late 14c., from astrology + -er (1). Drove out French import astrologein, which, had it survived, probably would have yielded *astrologian, as in Chaucer's "The wise Astrologen." Earliest recorded reference is to roosters as announcers of sunrise.[astrologer etymology, astrologer origin, 英语词源]