frosty (adj.)youdaoicibaDictYouDict[frosty 词源字典]
Old English forstig, fyrstig "as cold as frost;" see frost (n.) + -y (2). Figurative use from late 14c. Related: Frostily; frostiness. Similar formation in Dutch vorstig, German frostig.[frosty etymology, frosty origin, 英语词源]