This is the 245th most frequent Japanese word.
報告
Report.
'報告' here is used as a noun that is part of the compound verb '報告する' (to report), indicating the act of reporting something.
会議で新しいプロジェクトについて報告する予定です。
I plan to report about the new project in the meeting.
In this sentence, '報告' is used as a noun referring to 'a report' as an entity that can be sent.
報告が送られた後に全員に通知されます。
After the report is sent, everyone will be notified.
Here, '報告' is used as a noun meaning 'report' or 'a reporting action' and functions as the object of the verb 'しました' (did).