elfin (adj.)youdaoicibaDictYouDict[elfin 词源字典]
"of or pertaining to elves," 1590s, from elf; first found in Spenser, who also used it as a noun and might have been thinking of elven but the word also is a proper name in the Arthurian romances (Elphin).[elfin etymology, elfin origin, 英语词源]