leery (adj.)youdaoicibaDictYouDict[leery 词源字典]
"untrusting, suspicious, alert," 1718, originally slang, with -y (2), and perhaps from dialectal lere "learning, knowledge" (see lore), or from leer (v.) in some now-obscure sense. OED suggests connection with archaic leer (adj.) "empty, useless," a general Germanic word (cognate with German leer, Dutch laar), of unknown origin.[leery etymology, leery origin, 英语词源]