This is the 7676th most frequent Russian word.
заключение
"Заключение" - conclusion, imprisonment, or detention (depending on context).
In this sentence, "заключение" is used to mean the final statement or summary that concludes a speech or presentation.
Докладчик подытожил свою речь заключением.
The speaker concluded their speech with a conclusion.
In this usage, "заключение" represents the result or decision reached after analysis or reasoning.
На основании имеющихся данных они пришли к заключению.
Based on the available data, they came to a conclusion.
Here, "заключение" is used to mean imprisonment or detention.