fantastyoudaoicibaDictYouDict[fantast 词源字典]
"An impractical, impulsive person; a dreamer", Late 16th century (formerly also as phantast): originally via medieval Latin from Greek phantastēs 'boaster', from phantazein or phantazesthai (see fantastic); in modern use from German Phantast.[fantast etymology, fantast origin, 英语词源]