unannounced
🇺🇸
/ˌʌnəˈnaʊnst/
🇬🇧
/ˌʌnəˈnaʊnst/
adjective
R
Not previously mentioned or expected; arriving or occurring without warning.
The teacher made an unannounced visit to our class to check our progress.
老師未經宣佈就來我們班級檢查我們的進度。
translation
突襲