lichen (n.)youdaoicibaDictYouDict[lichen 词源字典]
c. 1600, from Latin lichen, from Greek leichen, originally "what eats around itself," probably from leichein "to lick" (see lick). Originally used of liverwort; the modern sense first recorded 1715. Related: Lichenaceous.[lichen etymology, lichen origin, 英语词源]