un·an·nounced /ˌʌnəˈnaʊnst◂/ adjectiveadj , adverb EXPECThappening without anyone expecting or knowing about it 出人意料的[地]；未经通报的[地] We arrived unannounced. 我们到得很突然。
unannounced• My brother is famous for showing up at our houses unannounced, usually around dinner time.• an unannounced visit• Investigators from the health department made unannounced visits to the hospital in March.