This is the 6297th most frequent Russian word.
усилиях
"Efforts" or "endeavors."
The word 'усилий' is used in the context of contributions and effort dedicated to achieving something.
Он приложил немало усилий к этому проекту.
He put a lot of effort into this project.
The word 'усилий' focuses on the prolonged and intense effort applied to overcome a challenge or problem.
После долгих усилий ему удалось решить задачу.
After long efforts, he succeeded in solving the problem.
Here 'усилий' refers to the extensive and selfless dedication put into aiding others.