unannounced
unan·noun·ced
adjective
1.
without warning or announcement
- “they arrived unannounced”
- “a totally unheralded telegram that his daughter...died last night” M.A.D.Howe
Origin
From un- + announced.
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.