sclero-youdaoicibaDictYouDict[sclero- 词源字典]
before vowels scler-, word-forming element meaning "hard," from Latinized form of Greek sklero-, comb. form of skleros "hard," related to skellein "to dry up, parch," from PIE *skle-ro-, from root *skele- "to parch, wither."[sclero- etymology, sclero- origin, 英语词源]