"a hole-and-corner life in some obscure community"
"clandestine intelligence operations" "cloak-and-dagger activities behind enemy lines" "hole-and-corner intrigue" "secret missions" "a secret agent" "secret sales of arms" "surreptitious mobilization of troops" "an undercover investigation" "underground resistance"
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)