unannounced
adj. 未经宣布的；未通知的；未打招呼的
近义词：unexpected，impromptu，surprise，spontaneous，unpredicted，unheralded，
英英释义
Adjective
- without warning or announcement;
"they arrived unannounced" "a totally unheralded telegram that his daughter...died last night"
例句
用作形容词(adj.)
- You're working on an unannounced MMO.你们正在开发一款未公布的网络游戏。
- 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。
- She just turned up unannounced on my doorstep.她未打招呼就来到我家门口了。