This is the 2362nd most frequent Russian word.
обвинение
Accusation or charge.
Here, 'обвинение' is used as a noun meaning 'accusation'—it refers to a formal statement asserting someone has committed a wrongdoing.
Это серьёзное обвинение требует тщательного расследования.
This serious accusation requires thorough investigation.
In this sentence, 'обвинения' (plural of 'обвинение') indicates multiple formal charges or claims of wrongdoing directed at someone.
Обвинения против него оказались ложными.
The accusations against him turned out to be false.
Here, 'обвинение' is used in a legal context to indicate a formal legal complaint initiated through a court system.