unannounced

adj.

未经宣布的；未通知的；

1. You're working on an unannounced MMO.
   你们正在开发一款未公布的网络游戏。
2. The manger dropped in unannounced at the office several times a week.
   经理每星期都不经事先通知到办公室来几次。
3. She just turned up unannounced on my doorstep.
   她未打招呼就来到我家门口了。

Unannounced standardised patients in real practice: a systematic literature review
Unannounced simulated patients' observations of physician STD/HIV prevention practices.
Provision of preventive care to unannounced standardized patients
Analysis and modelling of the unannounced evacuation of a large retail store
Adherence to Antiretroviral Therapy Assessed by Unannounced Pill Counts Conducted by Telephone
Way finding during fire evacuation; an analysis of unannounced fire drills in a hotel at night
Monitoring Medication Adherence by Unannounced Pill Counts Conducted by Telephone: Reliability and Criterion-Related Validity
Improving physicians’ HIV risk-assessment skills using announced and unannounced standardized patients
Comparing Objective Measures of Adherence to HIV Antiretroviral Therapy: Electronic Medication Monitors and Unannounced Pill Counts
Trials of teaching methods in basic life support (4): comparison of simulated CPR performance at unannounced home testing after conv...