This is the 678th most frequent Arabic word.
وأعلن
"وأعلن" means "and he/it announced" or "and declared."
"وأعلن" here emphasizes the act of revealing critical findings, combined with the sentiment of reaching the outcome after long efforts.
أخيراً وأعلن العالِم النتائج بعد سنوات من البحث.
Finally, the scientist announced the results after years of research.
Here "وأعلن" is used to signify delivering an official statement regarding a particular issue.
وأعلن المتحدث الرسمي موقف الحكومة حيال التطورات الأخيرة.
The official spokesperson announced the government's stance regarding the recent developments.
The word "وأعلن" here introduces the act of the manager announcing something, indicating formal communication of new information.